April 25, 2024 • 49 mins
There are many elements which affect how cold you feel and how cold you actually are at the core, in this episode Richard talks about the subtle external factors which can have a big impact on our bodies in lower temperatures.
We've covered hypothermia in previous episodes but the exact meaning of the term 'hypothermia factory' relates to the perfect mixture of cold and wet with some wind thrown in for good measure, the ideal conditions for pulling away the heat generated by your body.
Links
– Connect with Richard and Modern Outdoor Survival
– Modern Outdoor Survival on Instagram
– Richard on Instagram and Twitter
– Original Outdoors on Instagram, Twitter and Youtube
– Amy on Instagram and Twitter
– Join our Discord Community
We've covered hypothermia in previous episodes but the exact meaning of the term 'hypothermia factory' relates to the perfect mixture of cold and wet with some wind thrown in for good measure, the ideal conditions for pulling away the heat generated by your body.
Links
- Warming - an episode about hypothermia and first aid with Adam Gent of Real First Aid
- Fabric - Layering systems to stay safe
- Outdoor Swimming Society
- Wind chill calculators
– Connect with Richard and Modern Outdoor Survival
– Modern Outdoor Survival on Instagram
– Richard on Instagram and Twitter
– Original Outdoors on Instagram, Twitter and Youtube
– Amy on Instagram and Twitter
– Join our Discord Community
Mark as Played
Transcript
Episode Transcript
Available transcripts are automatically generated. Complete accuracy is not guaranteed.
(00:33):
Oh my god, Yeah, that'scold. Okay, this is this is
this is a podcast where I mustlet I swear, isn't it? Okay?
So this is welcome to another episodeof Modern Outdoor Survival. My name
is Richard. And because I amin my very early forties and I spent
(00:53):
too long listening to Joe Rogan podcastsand stuff like that, I have a
homemade cold plunged tank in the bottomof the garden and this is this is
a two and a half thousand literwater stock drinking water tank thing, and
it's not well. I think thiswas once a hot tub made a's a
(01:18):
diy thing by our friend crab boatStew and now it's it's it's this and
they use it for reducing inflammation andmeant to be repair and cold water stuff
and things I'm not gonna try andremember now. But this is this is
not an episode about cold water immersion. This is an episode about wet cold
(01:46):
versus dry cold. And it's notactually that cold in here. According to
the little floating thermometer thing, thiswater is what as I say, that
says here, it says it's aneight degrees centigrade celsius whatever, which I
think is about forty six in freedomfahrenheit units, but it's not actually that
(02:10):
cold, and the air temperature iseven warmer. That's about ten degrees or
I think it's about is that fifty? I don't know. I can't do
the maths. So this isn't evenfull immersion. This is just the bottom
half of me. This is fullimmersion. So the reason people use cold
(02:38):
water rather than just going into acold area, well, it's cheaper and
easier to do at home. Butwater will suck the heat away from your
body much quicker than air. Andif I do things like this to move
arms, then it will feel colderbecause if you sit perfectly still, you
(03:05):
build a little area of not warmbut not as cold water right next to
your skin. But if you moveyour arms, if you move your body,
you are constantly moving into colder wateraround you, and it makes you
feel colder. And there's all sortsof things the body's meant to be doing.
(03:27):
Now, with regards to all sortsof things, this is not what
the podcast is about. The podcastis about the difference between between wet and
cold and dry and cold. Sobecause it's going to sound well, let's
just face it's going to sound inappropriateif I keep talking like this throughout the
whole episode. I'm going to finishmy cold water immersion thing here, and
(03:53):
then we're going to cut to ussat at the table in the garden once
I've got out of here and I'veput some clothes on, so three two
one, So now I'm fully clothedagain and I'm sat here with a coffee
in the field, sitting in thesun. It's a bird in the hedgerow
behind me, is you can possiblyhear? This is a lovely spring day.
(04:15):
It's mid April here in the UK. It's been a late spring this
year. It's been really wet andwindy winter, so it hasn't been that
cold. It's just been wet andthere's we haven't had many days where there
hasn't been wind, and that's that'sreally a factor in what I'm about to
talk about with this episode. Thisepisode is something that I've had on my
(04:39):
list for a while that i wantedto cover because it's an important topic and
it's something that requires a bit ofa bit of subtlety and a bit of
subtlety in your understanding of it.It also partners really well with our next
episode. So our next episode isalready recorded. That is a story told
(05:00):
by friends of ours about a tripthat went wrong in the United States.
Nobody died, no long lasting injuries, but it is a really interesting story
and there are lots of learning pointsfrom that. So that's covered in the
next episode, but this one isa good partner to it. So I'm
(05:20):
going to be talking about dry coldversus wet cold, or another way of
saying that is the subtle factors thataffect how you feel temperature and how temperature
affects you in the outdoors. Becauseas humans were quite good at regulating our
(05:43):
body temperature with it across a widerange of temperatures. We have indigenous humans
in the far Arctic, and wehave indigenous humans on the equator and in
the hottest places on Earth. Sopeople have managed to adapt to a wide
bread of temperatures. But those environmentsare not equal to each other in any
(06:05):
way. Different humidities, different weatherpatterns, different amounts of daylight, sunlights,
angle of the sun, all ofthese things come into it when we're
doing stuff in the outdoors. Whereveryou are, when you're listening to this,
there are certain factors that will reallyaffect how you feel cold, how
(06:25):
temperature affects you. One of themis moisture, whether that is humidity in
the air, moisture on your skin, how wet your clothing is, whether
you're lying on wet ground versus dryerground. All of that comes down to
moisture and how that interacts with yourbody. The other aspect is a moving
(06:46):
element, whether it's wind moving acrossyour body or your body moving through air,
or whether it's water moving across yourbody and moving water versus still water.
So I'm going to cover the moisturewater aspect first, but before that,
I just want to quickly go througha refresher about what cold weather injuries
are or cold injuries. See,you tend to have two really that people
(07:10):
talk about and that are the mostobvious. One is hypothermia. So hypothermia
is defined as a core temperature corebeing not your fingers, your not your
face, not your forehead temperature,but right there in the middle of your
torso a core temperature of below thirtyfive degrees celsius. Average normal temperature for
(07:31):
people for humans is about thirty sevendegrees celsius. If that drops two degrees
then you have slipped into the startof mild hypothermia, and the three states
of medically defined hypothermia. There's mildhypothermia, which is anything below thirty five
(07:53):
to about thirty two degrees celsius.You have moderate, which is thirty two
down to twenty eight three cell,and then anything below twenty eight is the
core temperature is severe hypothermia, andthat brings in all sorts of other risks
as well. So you may haveheard these stories about people who've survived very
very cold temperatures and they've been rushedto hospital and they've appeared to be dead,
(08:16):
but upon medical intervention and other things, they have actually sort of come
back to life, or it seemslike they've come back to life. You
may have heard a phrase that you'renot dead until you're warm and dead.
If you've done any kind of outdoorfirst aid, any outdoor medical training,
you probably have come across that.And that's from that world. It's from
(08:37):
that phenomenon of if somebody is actuallyvery very cold and the cold was the
thing that put them into that state, they might appear to be dead.
We won't know for sure until we'vetried to rewarm them. So severe hypothermia
can look like death or can justlead to death, depending on the outcome.
(08:58):
So that's hypothermia. So a coretemperature dropping below thirty five degrees of
celsius. There's a bee attacking mecurrently, so that might be on the
microphone. Nature is a guest onthis podcast, Will you go away?
Thank you? Just feeling cold,feeling a bit chilly isn't hypothermia. Your
skin being cold to the touch isn'thypothermia. Just saying oh, I need
(09:22):
to rewarm is not hypothermia. Hypothermiais a medical designation, is a medical
limit of you have a core temperatureof below thirty five degrees celsius, but
you can feel cold and uncomfortable beforethat point. The second type of cold
injury frostbite, frost nip, skinfreezing, or skin starting to drop below
(09:46):
a temperature where it can self regulate. That is not hypothermia. That is
a separate injury. You can havea completely frozen hand. You can have
a hand that you've been dipped inliquid nitrogen or you've wrapped it in eye
so it's now completely frozen solid tothe core, and still have a core
temperature in the center of your bodyabove thirty five and you have not got
(10:09):
hypothermia. So these are two separateinjuries hypothermia, core temperature dropping below thirty
five degrees, frost bite, frostnip, those kind of things that is,
think about skin freezing or starting tofreeze. In this episode, we're
going to talk about hypothermia more.All the things we're going to talk about
will have an impact on frost nip, frost bite. And you do need
(10:33):
to be able to manage the temperatureof your extremities through clothing, through the
way you're using it, through preplanning, through careful use of these things.
And the cold of the temperature isand the more wind and wet stuff
there is around, you really needto be aware of that. But separate
(10:54):
the mount as to being two differentinjuries hypothermia and freezing skin freezing or starting
to freeze. So when your skinis wet, it could lose heat at
a rate four times faster than ifit were dry. How your skin gets
(11:16):
wet, how wet it is,the ambient temperature, what's happening with airflow
and stuff like that will all havean impact on that. But just know
that wet skin will lose heat morequickly the environment you're losing heat into matters.
So if you search for something calledwet bulb temperature, this is something
(11:39):
you might see lots of articles comingup now about climate change and how the
wet bulb temperature is actually more importantand the thing that we need to keep
an eye on more more than theactual dry temperature. So wet bulb there's
got nothing to do with light bulbs. It is imagine classic thermometer glass tube
(12:01):
thermometer that somebody has taken a wetpiece of fabric and wrapped it around the
bottom of the thermometer that reads thetemperature that expands and pushes the fluid up
or down. That is a wetbulb. So it is to do with
the humidity of the air, itis to do with the ambient temperature,
(12:22):
and it is to do with thedew point. So this is a thing
for meteorology and weather and those kindof observations. You're not going to be
sat there on the side of amountain calculating this, but know that there
is actually scientific observation around humidity andair temperature and the point at which water
(12:43):
will start to form and dewe pointsand so on. So you don't have
to understand any of that, butknow that yet to know that this being
wet versus dry is significant because andit will have an effect on the way
human observe and feel temperature around them. So if you were to stand out
(13:07):
somewhere in completely completely naked but withdry skin, in low temperatures, with
no air movement, you could standthere for longer and not feel the effects
of cold compared to being wet.If you had wet skin, if somebody
came along and soaked you with ahose, poured a bucket of water over
(13:28):
your head, you would feel thecold, but up to a four times
factor than if you were just completelydry in zero air. Those kind of
things don't tend to happen, though, I mean, unless you're in the
habit of diving under waterfalls, whenyou're out walking in the mountains, or
somebody follows you around with a wateringcan, you're probably not going to suddenly
(13:52):
get wet unless it rains, oryou'll hit by spray of some kind from
something else, or you get sweaty. And when you start to think about
things in those terms, you thinkis actually quite a lot of the natural
environment that will make you wet,will put you in that state of having
wet skin versus dry skin. Soyou need to be aware first of all
(14:18):
of when your skin is starting toget wet. The thing that causes that
you can mitigate to a degree.You cannot stand under the waterfall, you
cannot go out when it's rainy.You can only go out on dry weather,
and you can make sure that youdon't sweat. But I've been doing
this for quite a long time now, and if I didn't go out when
(14:39):
it was raining, then I'd nevergo out in the UK. That would
preclude any kind of water sports canoeing, paddling, stand up paddle boarding,
swimming, surfing, or any ofthe other stuff I like to do.
And my genetics just won't allow meto go out without sweating. Minus twenty
(15:00):
degrees celsius is about my happy temperaturefor not really sweating, and even then
for moving around and not sweat,not sweating anything more than that, if
I'm moving around, I'm generating sweatsomewhere on my body. Of all those
things, the sweat is the thingthat I really have to pay attention to.
So if I am somewhere where theair temperature around me is quite low.
(15:28):
I have to be really conscious ofhow sweaty I get, how much
sweat is building up in my baselayer, in my mid layer, on
the area next to my skin thatis difficult for me to get rid of.
I can moderate that to a degreeby moving slower. But if I
if I'm moving so slowly I can'tactually get anywhere, then I'm not really
(15:52):
doing the job I need to doin that place. If I'm walking from
somewhere to somewhere else, or I'mwalking up hill, or I'm snowshoeing,
or the few times I've been skiing, or anything like that, where I
need to move, then I needto move at a certain rate in order
to make progress. And if you'recarrying a rucksack, if you're walking uphill,
if you're doing something slightly harder,then you will be sweating more or
(16:14):
more likely too sweat. So Ineed to find a way to manage the
level of moisture on my body.It is harder in high humidity air,
so the amount of the moisture levelin the air. It is harder in
high humidity for sweat to evaporate away. So if it is high humidity and
(16:38):
my body is sweaty and my baselayer is sweaty, then it is going
to stay sweaty in lower humidity,really dry air. If I sweat,
that moisture is going to disappear quitequickly, so I won't stay wet for
very long. This is why,in the other end of the scale,
(16:59):
when you're talking about hyper thermia andbeing too hot, high humidity conditions and
high temperatures are more dangerous than hightemperatures and low humidity because it is harder
to cool down. In humid conditions. You'll be sweating, but your body
will just create a warm air ofwater around you and you won't. It
(17:22):
won't disappear, and you won't andyou'll just keep building up heat and building
up heat. Your sweat in colderconditions is not an advantage. It is
something that will make your life harder. It is more likely to send you
into a state of hypothermia because yourbody will then stay wet and you will
(17:44):
lose heat up to four times faster. So managing the moisture on your next
to your body is really important.I can't emphasize that enough. You can
just think, oh, well,I'm getting sweaty. It's a good workout,
or you know, look at this, or I'll just get sweaty.
But I don't mind being wet andsweaty. And I don't mind even if
your body is quite clean anyway,and you showered recently, then the sweat
(18:04):
probably won't smell. You might think, oh, yeah, I can deal
with it. But the moisture nextto your body is the problem, no
matter how it was formed. Sweatis a thing that means you could form
moisture next to your body through exerciseat a wide range of temperatures. At
lower temperatures, that is going tostart to become an issue. So in
(18:26):
cold temperatures you make sure you don'tbuild up a sweat, or even in
mild temperatures like we have now,if I was to stand around in the
shadow in the valley at the bottomof the mountain waiting for my mates to
get there, then i might bewearing my base layer. I'm a midlayer,
and then a jacket on top ofthat, and then I'm still wearing
that when I set off up thetrail, up the track and start walking
(18:48):
uphill, and I'll quickly build upsweat and start building up heat and then
start to sweat and I will haveto stop and then take those layers off
to get rid of that heat andstop me sweating. That's why when we
take people out into the mountains,and when we take clients out on trips
or we advise clients, we alwaysadvise a layering system. So then you
(19:11):
can have a layer that you justwear next to your skin that will absorb
some of that moisture and pull itaway from your body a little bit.
But you can just wear that,or you can wear another layer on top
of that, or a layer ontop of that, or a layer on
top of that, up to fourlayers. But those four layers means that
you mean that you can take offone layer, two layers, three layers
(19:33):
and still not be standing there toplessor bottomless. If it's that half on
the side of a mountain, youcan still have some degree of protection on
your body, but you will beable to regulate your temperature so you won't
sweat as much. The type offabric those layers are made from is how
you'll handle the sweat that you dogenerate anyway, So if you're walking uphill
(19:55):
with a rucksack and you're starting tosweat, you strip down to just your
base layer. If possible, youstart off taking off one layer, then
maybe a second layer. And forme most cases, I'm stripping right down
to my base layer, just tothe layer against my skin. I will
still be sweating there, but becausethat base layer is made from a fabric
that isn't cotton, so it's apolyester or more likely these days, a
(20:18):
marino wall type fabric, it willpull the moisture away from my body and
then try and get rid of itquite quickly. It won't saturate and hold
on to a lot of it.It will only hold out so much and
then try and push it out awayfrom my body. That will then evaporate
out into the air. It willmove out to other places. But the
(20:40):
fabric type that I've chosen will hopefullymean that that sweat layer doesn't stay next
to my body for too long.We've got other episodes that really cover that
and layering and how to manage thatbody. You're sweat next to your body,
but wet clothing, wet layers nextto your skin will mean you lose
heat more quickly. Do what youcan to reduce that sweat from building up.
(21:06):
If you have got wet clothing.If you have got a completely saturated
wet base layer from walking up hillslightly humid weather, it's not actually that
cold, but it's cold enough,and you're working hard walking up hill with
a heavy rucksackle or your mountain bikingin right in the bottom gear in granny
gear, grinding up the hill,trying to get up this trail, you
(21:30):
are probably going to build a levelof sweat. Anyway, Your next thing
is that when you stop, youare now stood there in wet clothing and
your body is losing heat. Ifyou stand there long enough and stay wet,
you will drop into hypothermia. Yourcore temperature will drop, your body
won't be able to regulate with thatamount of moisture on your skin. You
(21:52):
will drop into hypothermia. Eventually,you'll probably get bored and move on before
or you reach that point. Butif you have other factors like poor diet,
or you're not feeling particularly well thatday, or other factors like wind
and air movement on you, whichwill talk about in a moment, you
will develop hypothermia more quickly when youstop with a wet bas layer with wet
(22:18):
clothing against your skin. So whenyou do stop. That's when you want
to stop. Get a layer outof your bag, put it on top,
just for the moment you're stopping there, because then you've still got a
wet layer against your skin, butyou've added insulation on top of that to
reduce that heat loss a little bit. Not one hundred percent, and you
(22:41):
won't be able to do it onehundred percent, but you have reduced the
effects of that moisture against your skin. So when you're walking uphill with a
slightly sweaty base layer and you stopand you put a layer on to keep
warm, what you're doing there isyou're mitigating the effects of the wet base
layer as much as anything else.That's why it doesn't really matter whether you're
(23:04):
putting a nice puffy down jacket onor just a waterproof hard sholler. One
will feel nicer than the other.But really what you're doing is stopping the
moisture, pulling the heat away fromyour body as quick as it can,
because it's only pulling it out asfar as that next layer. If you
(23:25):
then had to stand in that placeand stay there for as long as possible,
So say you for some reason youhad to walk up this hill for
two hours and then stay in thatspot for the next two days. You
would want to try and get dryas quick as you can and remove that
moisture from your body. And onthe odd times, I've done that with
different jobs and different bits of work. Back years and years ago, when
(23:47):
we used to do mountain safety coverfor big races and things like that,
and we used to or either employpeople to do that or do it myself.
You'd be stationed out on the sideof a mountain for six hours watching
runners come passed, or mountain bikersor whatever the race was. I would
take a separate basse layer for that, and I'd walk up hill quickly with
(24:08):
a lot of gear, and thenstop and then change the bass layer out
to a nice dry one because ican walk down in the dry one.
But I've now taken away that moisturefrom my body. I've dried my skin
up by putting a dry bass layeron, and I can stand there for
a longer and be happier with dryskin rather than wet skin. I'm not
saying that you just carry fifteen basslayers with you for every mountain trip,
(24:30):
but you do consider the effects ofthat moisture on your skin. Monitor how
quickly your base layer is drying.If it's getting sweaty, how quickly is
it drying up. If you staywet for longer, you will cool down
more quickly. And this is wherethe problem with hypothermia comes in, because
(24:52):
you can get cold and get toa stage of hypothermia or mild hypothermia without
realizing it. You can look atyour body and go, well, I'm
still sweating. I can't be cold. But actually you're entering the early stages
of hypothermia, and you've started tolose some cognitive ability, some strength,
some flexibility, some ability to controlyour limbs. You've lost some dexterity in
(25:18):
your fingers, you've lost the abilityto carefully place your foot on the edge
of a rock and something like that. I've seen that before with clients in
the mountains, where they've started toenter the early stages of hypothermia, but
they haven't noticed because they still feela little bit too hot because they're really
sweaty. So's at these subtle edgesthat's where the difference comes in. So
(25:42):
be aware of the moisture on yourbody from sweat. The next thing is
rain and stuff like that. That'swhy we always say you should carry some
way of keeping your body dry.Hard shell waterproof layers I think generally are
better, or some kind of waterproofsystem like paramo or something that pulls moisture
(26:03):
away from your body and stop andif it's working properly, doesn't let rain
through. Your aim is to tryand keep your body as dry as possible.
And that's the main takeaway from thispart of it is keep your body
as dry as possible. If itdoes get wet, pay attention to how
wet it's got, how quickly it'sdrying out, and what it's doing to
(26:26):
you in that environment, and knowthat when your body is wet, it
is losing heat more quickly than ifit was dry. There are little micro
factors to this as well, likeif you're sat on wet ground, if
you're sat on a wet rock,you're going to be losing heat more quickly
than if you're sat on a dryrock. If you're touching wet surfaces,
(26:47):
you're going to lose heat more quicklythan if you're touching dry surfaces. All
of these things will make a difference. So try and keep your body dry
and try and manage that moisture.If you can't manage a moisture, if
you're doing something like swimming, ifyou're doing something like water sports where you're
going to be getting wet, youneed to be aware of that risk there
(27:12):
and manage it differently. So ifyou're swimming, and in the notes are
going to link out to the OutdoorSwimming Society, they've got some great notes
on cold water swimming and the effectsof your body of cold water and some
real myth busting and stuff like that. Your body's reaction to cold water is
(27:33):
something you really need to pay attentionto, and it's something you can acclimatize
to. And that's the part ofwhat I'm doing with a cold water tank.
And there's some other benefits to itas well. But you can acclimatize
to it, but it's not somethingthat you can just jump into. Cold
water needs management. The temperature doesn'thave to be that low for it to
(27:57):
be classified as cold water. Fivedegrees celsius, So what's up forty one
two degrees fahrenheit. That's a coldday, but it is if it was
the air temperature. But it's somethingthat you can deal with quite happily.
(28:18):
Five degrees water temperature in a riveror a lake or something like that,
that is going to give you tento twenty minutes, depending on your body
before you start to really lose coordination, lose strength, lose literally power in
your muscles, you can't move asmuch, you lose dexterity. You will
(28:41):
get to the point after about tento fifteen minutes in five degree water one
forty two fahrenheit degree water that youcan't pull yourself out of it. You
can't pull yourself back onto a dockor onto a boat. You can extend
your body's ability to deal with thoselower tens through training, and there are
all sorts of training programs for it. Some people are just naturally better at
(29:03):
it than others. The difference betweena slightly cool day on the shore and
you're in a survival situation the momentyou enter the water, it can be
the same temperature. So if you'redoing stuff around water, be prepared to
manage that risk of the water.So if you're swimming, if you're getting
(29:26):
in the water, if you're ina wet suit or something like that,
that's going to add some insulation ora dry suit even or an immersion suit.
That's really going to add some insulation, but it's going to bring its
own factors loss of mobility, lossof flexibility, extra weight, extra bulk,
whatever. But if you're getting inthe water, you manage it through
training. You manage it through awarenessof that temperature, and through just how
(29:49):
long you're spending in there and whatyou're going to do when you get back
on shore to rewarm. Be awareof being in that water, be aware
of your management strategies for it.The really dangerous areas I think are when
you're near the water, where youmight go into the water. And this
does and this is relevant to thenext episode, if you might end up
(30:12):
in the water, you should havea strategy for getting into that water.
You might think, well, it'snot frozen, it's fresh water, it's
not frozen, so it's got tobe above freezing, and I can deal
with temperatures above freezing. No.I mean, like, I was in
that cold water tank there for afew minutes or eight degrees and it was
(30:32):
starting to get unpleasant. And Inoticed because I actually had to spend longer
in there while we sorted out somestuff for the recording of the podcast.
So I spent sight long longer inthere than I normally would have done.
I lost some of the flexibility inmy legs, in my feet, my
toes, so I was stumbling slightlyas we got out in temperatures that would
(30:55):
I was happily working in in aT shirt yesterday when it was the air
temperature on land. So if you'reworking near water, either on a shore
or on rocks above it or somethinglike that, or more likely in a
boat, in a vessel of sometype, be prepared to enter that water
(31:15):
and what you're going to do afterwards, because if you enter the water and
the water temperature is even anything belowtwenty degrees eighteen degrees, it could quickly
and send you into a situation wherehypothermia is not just a real risk,
it is happening to you. Yourcore temperature can drop very very quickly.
(31:37):
You can lose dexterity in your fingers, you can lose the ability to think,
you can lose or at least toproblem solve. You can lose strengthen
your muscles. There's all sorts ofthings. We are breathing. We've got
the mammalian dive reflex, and youknow we can go into that, but
just think that if you enter thatcold water and it does not have to
be that cold, you are thenin a survival situation. If you enter
(32:04):
it unexpectedly, you're happily going alongdoing a thing, and now you're in
the water, then in many waysthat's worse because you haven't even got the
ability to mentally prepare for it.But if you're going somewhere where the water
is going to be cold or cooland there is a reasonable chance you could
(32:24):
end up in there, you shouldhave a management strategy for that before you
get there. So that strategy couldbe clothing, it could be spare clothing,
it could be what is attached toyour person. There are all sorts
of things around canoe journeys, andwe're going to talk about this in the
next episode and given away a littlebit what that's about, but how you
(32:46):
plan for that, but be preparedto enter that cold water and for you
then to be in a survival situationwhere you need to sort yourself out afterwards.
And if you're on your own,you're going to be already in a
(33:07):
position where it's harder to sort yourselfout, harder to fix that situation because
you are cold. So generally forif somebody has entered cold water and they've
become wet, and they have enteredcold moving water, particularly, then you
get them out onto the shore.You don't then keep them in their wet
(33:29):
clothing and add stuff on top.You get them out of the wet clothing
and get them dry as soon aspossible. If you're staying there in the
wet clothing, you are going tostill be losing heat, and you can
be pulling heat away from your bodyand crucially away from your core, and
(33:51):
send you into that state of hypothermiaquicker if you are wet. So get
them out of the water, getthem out of the wind, and we'll
talk about that. I keep teasingthis, but we'll talk about that shortly.
But get them out of the wetclothing and into dry clothing quickly.
(34:12):
The moisture is the real factor herethat you need to be aware of.
It's not just temperature. It's notokay, we'll make them warm and wet
rather than cold and wet. Okay, how about you make them warm and
dry. I keep emphasizing this.The rate at which the moisture pulls the
heat away from your body so muchhigher than dry clothing. Dry dry surfaces,
(34:34):
So manage that moisture, manage thatwater, manage that wetness as much
as the temperature. If you've onlygot one set of clothing with you and
that's all wet now, then youhave a problem. The whole point of
this podcast when we first started ita few years ago, was to counter
some of the stupid stuff we seeonline, some of the stupid stuff you
(34:55):
hear from other places, some ofthe stuff that's more about reinforcing a tough
man image or some other weird skewedthing about making things as uncomfortable for yourself
as possible, and instead push itback to what we know that works,
which is making good decisions and doinggood planning, make choosing good equipment,
(35:17):
doing the right things at the righttime, and some of those things you
had to have done weeks ago.And you can't just wait for a bad
situation to happen and then pull outyour magical piece of equipment that's going to
fix it all. If you enteredthat water without any way of getting warm
and dry soon after, it doesn'tmatter that you've got yourself out of the
(35:40):
river or out of the lake anddrag yourself onto the shore you're lying there
on a wet beach, in wetclothing, still losing heat, be losing
heat, maybe a little bit lessquickly than you were when you were in
the water, but you're still losingheat. Getting dry is really crucial here,
(36:01):
and that leads us on to thesecond part, which is a bit
I keep teasing wind. Any kindof moving air is going to be pulling
the little bit of heat that you'velost away from your body through the sweat,
which will make it pull away morequickly. But even in dry air,
on dry skin, rather, itwill pull that heat away from your
(36:22):
body much more quickly. Because imagineyou're standing there. You're standing there naked
in cool air, and your bodyis losing heat. It's losing heat from
what the surface you're touching, it'slosing heat from the breath coming out of
your mouth, it's losing heat throughradiation. But it is losing heat just
(36:43):
by warming up the area of airaround your body. So think about little
invisible suit you're wearing of heat beingpulled out, warming up a little zone
of air and next to your body. If you then were to grab that
little zone of heat and pull itaway from you, lost that heat and
you can't get it back. That'swhat wind does. It pulls this little
(37:05):
zone of warmth you have around youand pushes it off over there where it's
of no use to you. Soit's like being sucked away from you like
smoke. Insulating clothing helps reduce thisby keeping the little warm area of heat
next to your body under that clothing, under that insulation. But if you
(37:29):
take it off, the air canthen pull it away, or even on
a day without wind, if you'removing through it, you're leaving that heat
behind. So if you're mountain biking, or you're cycling or on a motorbike
or whatever, you're leaving even ona day without wind, you're leaving the
heat behind you. And you've probablyexperienced this when you go downhill and you
(37:50):
go down, you go or yougo faster, you feel cooler because I
think there was a nice breeze nowmoving. No, what's happening is all
of the heat that you're losing fromyour body. As soon as it leaves
your body, it's gone. It'soff there behind you somewhere. You're leaving
little zone of heat behind you.Slightly weird thing to think about, but
is kind it's an important concept toget that. If there's movement of air
(38:15):
around your body, whether it's throughwind or whether you're creating it. Because
you're moving through still air, you'releaving the heat behind or the heat's being
pulled away from you. So eventhough you might you might be losing heat
at a set rate because you've gotdry skin or wet skin or all that
stuff we've talked about, the factthat the air is pulling it away means
(38:37):
that that will be happening more quickly. So you may have heard the term
wind chill, and there are allsorts of wind chill calculators you can find
online, and I think we'll linkout to a couple, but they're all
a bit weird because it still doesn'tadequately reflect the temperature you'll feel in that
(38:58):
environment. So one windshield calculator weuse says that if the ambient temperature or
the air temperature around you is minuseighteen celsius and the zero wind, that's
about thirty minutes in that temperature beforeyou start to really develop any kind of
(39:19):
cold weather injury and for an averageperson, and really start to feel that
the effects of that cold in ameaningful way. But if you add a
fifteen mile an hour wind to thatminus eighteen temperature, or it's about twenty
four kilometers an hour, it's goingto feel like you were stood in minus
twenty eight celsius. Still there.That's all in dry conditions. If you
(39:45):
were wet in either of those conditions, so wet skin, minus eighteen celsius,
no air movement, you're in abad state. You're not going to
be lasting very long at all.If there was a fifteen mile an hour
wind and it's minus eighteen and you'rewet, I don't fancy your chances.
(40:06):
You've got to sort this situation outpretty quickly or you're going to die.
So all of that stuff I saidabout wet clothing being wet, wet through
sweat, wet through rain, wetthrough immersion into water, If you factor
in air movement on top of that, it starts to become a real issue.
(40:27):
And that's why it's still an issueeven though we're not in the depths
of winter now and here in theUK we didn't really have the depths of
the winter. Barely went blow freezing, but it was wet most days,
and it was windy most days,and I've had quite a few days this
winter where I've been working out inthe fields, working in the woodlands,
doing the other work we do,where I felt I'm on the edge of
(40:50):
mild hypothermia here because I'm wet andthe wind is pulling the heat away from
me. So I've had to choosemy clothing to reflect that, and I've
been having to balance out. Okay, i need a windproof layer of some
kind to stop that heat being pulledaway from me by the wind. But
if I'm working in a windproof layer, I'm going to get sweaty, so
(41:10):
I'll have wet clothing. So I'vehad to bring two or three different layers
out with me on different days toachieve different things. Managing body temperature in
wet conditions and in windy conditions,I think is much much harder than managing
body temperature in sub zero Arctic dryconditions. Scottish winter. Scottish wet winter
(41:38):
is a harder environmental I've found todeal with than high Himalayan mounting cold dry
air, because that moisture is areal factor, the wind is a real
factor, and together that is ahyperthermia factory. And I worry more about
(41:59):
hyperthermia. Don't do about frostbite,frost nip, those kind of things,
because the hypothermia creeps up upon youon days when you don't even think about
it because you're wet and it's slightlywindy. So the wind is an easy
one to talk about. And thefaster the wind, the more quickly it's
going to pull the heat away fromyou, and the more the colder you
(42:21):
will feel. Water is another factorwith this. You've got the water on
your skin pulling the heat away fourtimes faster. But and if you do
cold the cold plunge thing, oryou used to go swimming in cold water,
you'll know what this feels like.If you stay completely still in still
water in cold water, you caneventually feel like you're starting to acclimatize to
(42:45):
it, because what you're doing isbuilding up a little bubble of warm urh
not warm warmer water right next toyour skin. You're still losing heat into
that zone, and you will develophyperthermia eventually. If you stand there but
you've got this little warm area rightnext to your skin and it doesn't feel
quite as bad, and then swirlyour arms around and move around, you
(43:07):
will immediately feel much much colder,because what you're doing is the equivalent of
that wind pulling the heat away fromyour body. You're moving into colder water
all the time, and your bodyhasn't got a chance to heat up a
little layer next to it. It'sjust moving it around all the time.
So that's why moving water will alwaysfeel colder than completely still water, or
(43:34):
if you're moving through the water.So if you stand, if you float
completely still, it's submerged in water, the water doesn't move, you don't
move, you will feel warmer thanif you start swimming through it. You
might build up some heat inside andyour core through the exercise of swimming,
and that will have its own effect, But immediately you will feel colder because
(43:54):
you've started moving through the water,or if the water starts moving around,
or if you're in a river,that heat is being pulled away from you
straight away. So the movement ofthat little warm zone next to your body
from either wind or water in theoutdoors is going to be another factor.
(44:15):
So these are the two things.If your body gets wet, it will
lose heat much more quickly if yourbody is an environment where the heat is
being pulled away from you. Butby either airflow or water flow, you
will lose heat a lot more quickly. If you are wet and an environment
where there is airflow around you,you are going to lose heat very quickly.
(44:39):
If you are in cold water andit is moving or you're moving through
it, you will lose heat veryquickly. So you've got to be aware
of those two things, moisture movement, and that's why it's taken a whole
episode to go through this, andit's a really subtle thing to get your
(45:02):
head around because how you deal withit, how you manage it, is
going to be very dependent on whatyou're doing, what the temperature is,
what you're going to be doing next, what equipment you have with you,
how you're using that equipment. Waymore than we can go into with this,
this is part of good outdoor skills, which you've got to go out
(45:23):
and make mistakes and make soft mistakes, makes lots of little mistakes and get
cold and uncomfortable in a way thatyou can recover from and that where you
can do safely and learn what happens. We could talk about, as I've
talked about a lot in this episode, walking up hill with a rucksack,
but I could do a whole episodeon managing your body for moisture and air
(45:45):
temperature and moving air when mountain bikingversus road cycling. Do another one for
swimming, do another one for canoeing. All of these things, all of
these activities in these different environments.You've got to manage yourself else. But
take that away colder temperatures hypothermia.Think about the moisture on your body and
(46:08):
how that is held there, andwhat's happening with that moisture, how it
got there, what you're doing tokeep it out, what you're doing to
get rid of it, what you'redoing to prevent it happening again, what
you're doing to stop the effects ofthat moisture by changing into other layers.
And then the movement of things aroundyour body, air or water, those
two factors. If you can managethose and think about those, that is
(46:30):
going to be your best chance atpreventing hypothermia. But remember, hypothermia is
different to frostbite, it's different tofrost nip. It is a completely separate
designation hypothermia. Drop core temperature dropsblow thirty five and then you have mild,
moderate, and severe. That isthe takeaway. It's moisture management,
(46:52):
wet management, water management, whateveryou want to call it, and movement
management. What's that window to you? How much in the wind are you?
What are you doing to reduce theeffects of it? How prepared are
you for it? Or moving waterversus still water. I don't think I
can break it down any more thanthat without giving hyper specific examples. So
(47:15):
now we're going to move on totalking about things in the after show.
So thank you for listening, andkeep an ear out for that next episode
because it really ties into this oneand it comes up with some really practical
examples of what happens when this doesn'tgo quite as well as you hoped.
Thank you for listening to this episodeof Modern Outdoor Survival from Original Outdoors.
(47:36):
If you go along to Modern OutdoorSurvival dot com. There you will find
links to all of the content andeverything we've talked about in this episode,
plus links to all of the previousepisodes and the show notes for those episodes.
You will also find links to ourPatreon page where you can become a
supporter of the show and get ridof all of those pesky adverts and access
(47:58):
to bonus extra content and stuff thatthe public never gets to hear, and
behind the scenes stuff and a fewother things that are hidden away within there.
You've also got our Instagram account whichis at Modern Outdoor Survival. We
don't post on their huge amount,but we do post photos from things that
we talk about in the episodes.You will also find a link to our
(48:20):
discord platform where we have a groupfor Original Outdoors as a wider community.
There you can meet and talk topeople and discuss things, but all with
the anonymity of an early two thousand'sforum or bulletin board. It's a nice
retro way of going about things.I'm going to leave you now with our
three principles of Modern outdoor Survival andthey are Number one, make good decisions
(48:46):
at the right times. Number two, prioritize training over shiny new equipment.
Number three remember Instagram is not yourtraining provider. Five
Oh my god, Yeah, that'scold. Okay, this is this is
this is a podcast where I mustlet I swear, isn't it? Okay?
So this is welcome to another episodeof Modern Outdoor Survival. My name
is Richard. And because I amin my very early forties and I spent
(00:53):
too long listening to Joe Rogan podcastsand stuff like that, I have a
homemade cold plunged tank in the bottomof the garden and this is this is
a two and a half thousand literwater stock drinking water tank thing, and
it's not well. I think thiswas once a hot tub made a's a
(01:18):
diy thing by our friend crab boatStew and now it's it's it's this and
they use it for reducing inflammation andmeant to be repair and cold water stuff
and things I'm not gonna try andremember now. But this is this is
not an episode about cold water immersion. This is an episode about wet cold
(01:46):
versus dry cold. And it's notactually that cold in here. According to
the little floating thermometer thing, thiswater is what as I say, that
says here, it says it's aneight degrees centigrade celsius whatever, which I
think is about forty six in freedomfahrenheit units, but it's not actually that
(02:10):
cold, and the air temperature iseven warmer. That's about ten degrees or
I think it's about is that fifty? I don't know. I can't do
the maths. So this isn't evenfull immersion. This is just the bottom
half of me. This is fullimmersion. So the reason people use cold
(02:38):
water rather than just going into acold area, well, it's cheaper and
easier to do at home. Butwater will suck the heat away from your
body much quicker than air. Andif I do things like this to move
arms, then it will feel colderbecause if you sit perfectly still, you
(03:05):
build a little area of not warmbut not as cold water right next to
your skin. But if you moveyour arms, if you move your body,
you are constantly moving into colder wateraround you, and it makes you
feel colder. And there's all sortsof things the body's meant to be doing.
(03:27):
Now, with regards to all sortsof things, this is not what
the podcast is about. The podcastis about the difference between between wet and
cold and dry and cold. Sobecause it's going to sound well, let's
just face it's going to sound inappropriateif I keep talking like this throughout the
whole episode. I'm going to finishmy cold water immersion thing here, and
(03:53):
then we're going to cut to ussat at the table in the garden once
I've got out of here and I'veput some clothes on, so three two
one, So now I'm fully clothedagain and I'm sat here with a coffee
in the field, sitting in thesun. It's a bird in the hedgerow
behind me, is you can possiblyhear? This is a lovely spring day.
(04:15):
It's mid April here in the UK. It's been a late spring this
year. It's been really wet andwindy winter, so it hasn't been that
cold. It's just been wet andthere's we haven't had many days where there
hasn't been wind, and that's that'sreally a factor in what I'm about to
talk about with this episode. Thisepisode is something that I've had on my
(04:39):
list for a while that i wantedto cover because it's an important topic and
it's something that requires a bit ofa bit of subtlety and a bit of
subtlety in your understanding of it.It also partners really well with our next
episode. So our next episode isalready recorded. That is a story told
(05:00):
by friends of ours about a tripthat went wrong in the United States.
Nobody died, no long lasting injuries, but it is a really interesting story
and there are lots of learning pointsfrom that. So that's covered in the
next episode, but this one isa good partner to it. So I'm
(05:20):
going to be talking about dry coldversus wet cold, or another way of
saying that is the subtle factors thataffect how you feel temperature and how temperature
affects you in the outdoors. Becauseas humans were quite good at regulating our
(05:43):
body temperature with it across a widerange of temperatures. We have indigenous humans
in the far Arctic, and wehave indigenous humans on the equator and in
the hottest places on Earth. Sopeople have managed to adapt to a wide
bread of temperatures. But those environmentsare not equal to each other in any
(06:05):
way. Different humidities, different weatherpatterns, different amounts of daylight, sunlights,
angle of the sun, all ofthese things come into it when we're
doing stuff in the outdoors. Whereveryou are, when you're listening to this,
there are certain factors that will reallyaffect how you feel cold, how
(06:25):
temperature affects you. One of themis moisture, whether that is humidity in
the air, moisture on your skin, how wet your clothing is, whether
you're lying on wet ground versus dryerground. All of that comes down to
moisture and how that interacts with yourbody. The other aspect is a moving
(06:46):
element, whether it's wind moving acrossyour body or your body moving through air,
or whether it's water moving across yourbody and moving water versus still water.
So I'm going to cover the moisturewater aspect first, but before that,
I just want to quickly go througha refresher about what cold weather injuries
are or cold injuries. See,you tend to have two really that people
(07:10):
talk about and that are the mostobvious. One is hypothermia. So hypothermia
is defined as a core temperature corebeing not your fingers, your not your
face, not your forehead temperature,but right there in the middle of your
torso a core temperature of below thirtyfive degrees celsius. Average normal temperature for
(07:31):
people for humans is about thirty sevendegrees celsius. If that drops two degrees
then you have slipped into the startof mild hypothermia, and the three states
of medically defined hypothermia. There's mildhypothermia, which is anything below thirty five
(07:53):
to about thirty two degrees celsius.You have moderate, which is thirty two
down to twenty eight three cell,and then anything below twenty eight is the
core temperature is severe hypothermia, andthat brings in all sorts of other risks
as well. So you may haveheard these stories about people who've survived very
very cold temperatures and they've been rushedto hospital and they've appeared to be dead,
(08:16):
but upon medical intervention and other things, they have actually sort of come
back to life, or it seemslike they've come back to life. You
may have heard a phrase that you'renot dead until you're warm and dead.
If you've done any kind of outdoorfirst aid, any outdoor medical training,
you probably have come across that.And that's from that world. It's from
(08:37):
that phenomenon of if somebody is actuallyvery very cold and the cold was the
thing that put them into that state, they might appear to be dead.
We won't know for sure until we'vetried to rewarm them. So severe hypothermia
can look like death or can justlead to death, depending on the outcome.
(08:58):
So that's hypothermia. So a coretemperature dropping below thirty five degrees of
celsius. There's a bee attacking mecurrently, so that might be on the
microphone. Nature is a guest onthis podcast, Will you go away?
Thank you? Just feeling cold,feeling a bit chilly isn't hypothermia. Your
skin being cold to the touch isn'thypothermia. Just saying oh, I need
(09:22):
to rewarm is not hypothermia. Hypothermiais a medical designation, is a medical
limit of you have a core temperatureof below thirty five degrees celsius, but
you can feel cold and uncomfortable beforethat point. The second type of cold
injury frostbite, frost nip, skinfreezing, or skin starting to drop below
(09:46):
a temperature where it can self regulate. That is not hypothermia. That is
a separate injury. You can havea completely frozen hand. You can have
a hand that you've been dipped inliquid nitrogen or you've wrapped it in eye
so it's now completely frozen solid tothe core, and still have a core
temperature in the center of your bodyabove thirty five and you have not got
(10:09):
hypothermia. So these are two separateinjuries hypothermia, core temperature dropping below thirty
five degrees, frost bite, frostnip, those kind of things that is,
think about skin freezing or starting tofreeze. In this episode, we're
going to talk about hypothermia more.All the things we're going to talk about
will have an impact on frost nip, frost bite. And you do need
(10:33):
to be able to manage the temperatureof your extremities through clothing, through the
way you're using it, through preplanning, through careful use of these things.
And the cold of the temperature isand the more wind and wet stuff
there is around, you really needto be aware of that. But separate
(10:54):
the mount as to being two differentinjuries hypothermia and freezing skin freezing or starting
to freeze. So when your skinis wet, it could lose heat at
a rate four times faster than ifit were dry. How your skin gets
(11:16):
wet, how wet it is,the ambient temperature, what's happening with airflow
and stuff like that will all havean impact on that. But just know
that wet skin will lose heat morequickly the environment you're losing heat into matters.
So if you search for something calledwet bulb temperature, this is something
(11:39):
you might see lots of articles comingup now about climate change and how the
wet bulb temperature is actually more importantand the thing that we need to keep
an eye on more more than theactual dry temperature. So wet bulb there's
got nothing to do with light bulbs. It is imagine classic thermometer glass tube
(12:01):
thermometer that somebody has taken a wetpiece of fabric and wrapped it around the
bottom of the thermometer that reads thetemperature that expands and pushes the fluid up
or down. That is a wetbulb. So it is to do with
the humidity of the air, itis to do with the ambient temperature,
(12:22):
and it is to do with thedew point. So this is a thing
for meteorology and weather and those kindof observations. You're not going to be
sat there on the side of amountain calculating this, but know that there
is actually scientific observation around humidity andair temperature and the point at which water
(12:43):
will start to form and dewe pointsand so on. So you don't have
to understand any of that, butknow that yet to know that this being
wet versus dry is significant because andit will have an effect on the way
human observe and feel temperature around them. So if you were to stand out
(13:07):
somewhere in completely completely naked but withdry skin, in low temperatures, with
no air movement, you could standthere for longer and not feel the effects
of cold compared to being wet.If you had wet skin, if somebody
came along and soaked you with ahose, poured a bucket of water over
(13:28):
your head, you would feel thecold, but up to a four times
factor than if you were just completelydry in zero air. Those kind of
things don't tend to happen, though, I mean, unless you're in the
habit of diving under waterfalls, whenyou're out walking in the mountains, or
somebody follows you around with a wateringcan, you're probably not going to suddenly
(13:52):
get wet unless it rains, oryou'll hit by spray of some kind from
something else, or you get sweaty. And when you start to think about
things in those terms, you thinkis actually quite a lot of the natural
environment that will make you wet,will put you in that state of having
wet skin versus dry skin. Soyou need to be aware first of all
(14:18):
of when your skin is starting toget wet. The thing that causes that
you can mitigate to a degree.You cannot stand under the waterfall, you
cannot go out when it's rainy.You can only go out on dry weather,
and you can make sure that youdon't sweat. But I've been doing
this for quite a long time now, and if I didn't go out when
(14:39):
it was raining, then I'd nevergo out in the UK. That would
preclude any kind of water sports canoeing, paddling, stand up paddle boarding,
swimming, surfing, or any ofthe other stuff I like to do.
And my genetics just won't allow meto go out without sweating. Minus twenty
(15:00):
degrees celsius is about my happy temperaturefor not really sweating, and even then
for moving around and not sweat,not sweating anything more than that, if
I'm moving around, I'm generating sweatsomewhere on my body. Of all those
things, the sweat is the thingthat I really have to pay attention to.
So if I am somewhere where theair temperature around me is quite low.
(15:28):
I have to be really conscious ofhow sweaty I get, how much
sweat is building up in my baselayer, in my mid layer, on
the area next to my skin thatis difficult for me to get rid of.
I can moderate that to a degreeby moving slower. But if I
if I'm moving so slowly I can'tactually get anywhere, then I'm not really
(15:52):
doing the job I need to doin that place. If I'm walking from
somewhere to somewhere else, or I'mwalking up hill, or I'm snowshoeing,
or the few times I've been skiing, or anything like that, where I
need to move, then I needto move at a certain rate in order
to make progress. And if you'recarrying a rucksack, if you're walking uphill,
if you're doing something slightly harder,then you will be sweating more or
(16:14):
more likely too sweat. So Ineed to find a way to manage the
level of moisture on my body.It is harder in high humidity air,
so the amount of the moisture levelin the air. It is harder in
high humidity for sweat to evaporate away. So if it is high humidity and
(16:38):
my body is sweaty and my baselayer is sweaty, then it is going
to stay sweaty in lower humidity,really dry air. If I sweat,
that moisture is going to disappear quitequickly, so I won't stay wet for
very long. This is why,in the other end of the scale,
(16:59):
when you're talking about hyper thermia andbeing too hot, high humidity conditions and
high temperatures are more dangerous than hightemperatures and low humidity because it is harder
to cool down. In humid conditions. You'll be sweating, but your body
will just create a warm air ofwater around you and you won't. It
(17:22):
won't disappear, and you won't andyou'll just keep building up heat and building
up heat. Your sweat in colderconditions is not an advantage. It is
something that will make your life harder. It is more likely to send you
into a state of hypothermia because yourbody will then stay wet and you will
(17:44):
lose heat up to four times faster. So managing the moisture on your next
to your body is really important.I can't emphasize that enough. You can
just think, oh, well,I'm getting sweaty. It's a good workout,
or you know, look at this, or I'll just get sweaty.
But I don't mind being wet andsweaty. And I don't mind even if
your body is quite clean anyway,and you showered recently, then the sweat
(18:04):
probably won't smell. You might think, oh, yeah, I can deal
with it. But the moisture nextto your body is the problem, no
matter how it was formed. Sweatis a thing that means you could form
moisture next to your body through exerciseat a wide range of temperatures. At
lower temperatures, that is going tostart to become an issue. So in
(18:26):
cold temperatures you make sure you don'tbuild up a sweat, or even in
mild temperatures like we have now,if I was to stand around in the
shadow in the valley at the bottomof the mountain waiting for my mates to
get there, then i might bewearing my base layer. I'm a midlayer,
and then a jacket on top ofthat, and then I'm still wearing
that when I set off up thetrail, up the track and start walking
(18:48):
uphill, and I'll quickly build upsweat and start building up heat and then
start to sweat and I will haveto stop and then take those layers off
to get rid of that heat andstop me sweating. That's why when we
take people out into the mountains,and when we take clients out on trips
or we advise clients, we alwaysadvise a layering system. So then you
(19:11):
can have a layer that you justwear next to your skin that will absorb
some of that moisture and pull itaway from your body a little bit.
But you can just wear that,or you can wear another layer on top
of that, or a layer ontop of that, or a layer on
top of that, up to fourlayers. But those four layers means that
you mean that you can take offone layer, two layers, three layers
(19:33):
and still not be standing there toplessor bottomless. If it's that half on
the side of a mountain, youcan still have some degree of protection on
your body, but you will beable to regulate your temperature so you won't
sweat as much. The type offabric those layers are made from is how
you'll handle the sweat that you dogenerate anyway, So if you're walking uphill
(19:55):
with a rucksack and you're starting tosweat, you strip down to just your
base layer. If possible, youstart off taking off one layer, then
maybe a second layer. And forme most cases, I'm stripping right down
to my base layer, just tothe layer against my skin. I will
still be sweating there, but becausethat base layer is made from a fabric
that isn't cotton, so it's apolyester or more likely these days, a
(20:18):
marino wall type fabric, it willpull the moisture away from my body and
then try and get rid of itquite quickly. It won't saturate and hold
on to a lot of it.It will only hold out so much and
then try and push it out awayfrom my body. That will then evaporate
out into the air. It willmove out to other places. But the
(20:40):
fabric type that I've chosen will hopefullymean that that sweat layer doesn't stay next
to my body for too long.We've got other episodes that really cover that
and layering and how to manage thatbody. You're sweat next to your body,
but wet clothing, wet layers nextto your skin will mean you lose
heat more quickly. Do what youcan to reduce that sweat from building up.
(21:06):
If you have got wet clothing.If you have got a completely saturated
wet base layer from walking up hillslightly humid weather, it's not actually that
cold, but it's cold enough,and you're working hard walking up hill with
a heavy rucksackle or your mountain bikingin right in the bottom gear in granny
gear, grinding up the hill,trying to get up this trail, you
(21:30):
are probably going to build a levelof sweat. Anyway, Your next thing
is that when you stop, youare now stood there in wet clothing and
your body is losing heat. Ifyou stand there long enough and stay wet,
you will drop into hypothermia. Yourcore temperature will drop, your body
won't be able to regulate with thatamount of moisture on your skin. You
(21:52):
will drop into hypothermia. Eventually,you'll probably get bored and move on before
or you reach that point. Butif you have other factors like poor diet,
or you're not feeling particularly well thatday, or other factors like wind
and air movement on you, whichwill talk about in a moment, you
will develop hypothermia more quickly when youstop with a wet bas layer with wet
(22:18):
clothing against your skin. So whenyou do stop. That's when you want
to stop. Get a layer outof your bag, put it on top,
just for the moment you're stopping there, because then you've still got a
wet layer against your skin, butyou've added insulation on top of that to
reduce that heat loss a little bit. Not one hundred percent, and you
(22:41):
won't be able to do it onehundred percent, but you have reduced the
effects of that moisture against your skin. So when you're walking uphill with a
slightly sweaty base layer and you stopand you put a layer on to keep
warm, what you're doing there isyou're mitigating the effects of the wet base
layer as much as anything else.That's why it doesn't really matter whether you're
(23:04):
putting a nice puffy down jacket onor just a waterproof hard sholler. One
will feel nicer than the other.But really what you're doing is stopping the
moisture, pulling the heat away fromyour body as quick as it can,
because it's only pulling it out asfar as that next layer. If you
(23:25):
then had to stand in that placeand stay there for as long as possible,
So say you for some reason youhad to walk up this hill for
two hours and then stay in thatspot for the next two days. You
would want to try and get dryas quick as you can and remove that
moisture from your body. And onthe odd times, I've done that with
different jobs and different bits of work. Back years and years ago, when
(23:47):
we used to do mountain safety coverfor big races and things like that,
and we used to or either employpeople to do that or do it myself.
You'd be stationed out on the sideof a mountain for six hours watching
runners come passed, or mountain bikersor whatever the race was. I would
take a separate basse layer for that, and I'd walk up hill quickly with
(24:08):
a lot of gear, and thenstop and then change the bass layer out
to a nice dry one because ican walk down in the dry one.
But I've now taken away that moisturefrom my body. I've dried my skin
up by putting a dry bass layeron, and I can stand there for
a longer and be happier with dryskin rather than wet skin. I'm not
saying that you just carry fifteen basslayers with you for every mountain trip,
(24:30):
but you do consider the effects ofthat moisture on your skin. Monitor how
quickly your base layer is drying.If it's getting sweaty, how quickly is
it drying up. If you staywet for longer, you will cool down
more quickly. And this is wherethe problem with hypothermia comes in, because
(24:52):
you can get cold and get toa stage of hypothermia or mild hypothermia without
realizing it. You can look atyour body and go, well, I'm
still sweating. I can't be cold. But actually you're entering the early stages
of hypothermia, and you've started tolose some cognitive ability, some strength,
some flexibility, some ability to controlyour limbs. You've lost some dexterity in
(25:18):
your fingers, you've lost the abilityto carefully place your foot on the edge
of a rock and something like that. I've seen that before with clients in
the mountains, where they've started toenter the early stages of hypothermia, but
they haven't noticed because they still feela little bit too hot because they're really
sweaty. So's at these subtle edgesthat's where the difference comes in. So
(25:42):
be aware of the moisture on yourbody from sweat. The next thing is
rain and stuff like that. That'swhy we always say you should carry some
way of keeping your body dry.Hard shell waterproof layers I think generally are
better, or some kind of waterproofsystem like paramo or something that pulls moisture
(26:03):
away from your body and stop andif it's working properly, doesn't let rain
through. Your aim is to tryand keep your body as dry as possible.
And that's the main takeaway from thispart of it is keep your body
as dry as possible. If itdoes get wet, pay attention to how
wet it's got, how quickly it'sdrying out, and what it's doing to
(26:26):
you in that environment, and knowthat when your body is wet, it
is losing heat more quickly than ifit was dry. There are little micro
factors to this as well, likeif you're sat on wet ground, if
you're sat on a wet rock,you're going to be losing heat more quickly
than if you're sat on a dryrock. If you're touching wet surfaces,
(26:47):
you're going to lose heat more quicklythan if you're touching dry surfaces. All
of these things will make a difference. So try and keep your body dry
and try and manage that moisture.If you can't manage a moisture, if
you're doing something like swimming, ifyou're doing something like water sports where you're
going to be getting wet, youneed to be aware of that risk there
(27:12):
and manage it differently. So ifyou're swimming, and in the notes are
going to link out to the OutdoorSwimming Society, they've got some great notes
on cold water swimming and the effectsof your body of cold water and some
real myth busting and stuff like that. Your body's reaction to cold water is
(27:33):
something you really need to pay attentionto, and it's something you can acclimatize
to. And that's the part ofwhat I'm doing with a cold water tank.
And there's some other benefits to itas well. But you can acclimatize
to it, but it's not somethingthat you can just jump into. Cold
water needs management. The temperature doesn'thave to be that low for it to
(27:57):
be classified as cold water. Fivedegrees celsius, So what's up forty one
two degrees fahrenheit. That's a coldday, but it is if it was
the air temperature. But it's somethingthat you can deal with quite happily.
(28:18):
Five degrees water temperature in a riveror a lake or something like that,
that is going to give you tento twenty minutes, depending on your body
before you start to really lose coordination, lose strength, lose literally power in
your muscles, you can't move asmuch, you lose dexterity. You will
(28:41):
get to the point after about tento fifteen minutes in five degree water one
forty two fahrenheit degree water that youcan't pull yourself out of it. You
can't pull yourself back onto a dockor onto a boat. You can extend
your body's ability to deal with thoselower tens through training, and there are
all sorts of training programs for it. Some people are just naturally better at
(29:03):
it than others. The difference betweena slightly cool day on the shore and
you're in a survival situation the momentyou enter the water, it can be
the same temperature. So if you'redoing stuff around water, be prepared to
manage that risk of the water.So if you're swimming, if you're getting
(29:26):
in the water, if you're ina wet suit or something like that,
that's going to add some insulation ora dry suit even or an immersion suit.
That's really going to add some insulation, but it's going to bring its
own factors loss of mobility, lossof flexibility, extra weight, extra bulk,
whatever. But if you're getting inthe water, you manage it through
training. You manage it through awarenessof that temperature, and through just how
(29:49):
long you're spending in there and whatyou're going to do when you get back
on shore to rewarm. Be awareof being in that water, be aware
of your management strategies for it.The really dangerous areas I think are when
you're near the water, where youmight go into the water. And this
does and this is relevant to thenext episode, if you might end up
(30:12):
in the water, you should havea strategy for getting into that water.
You might think, well, it'snot frozen, it's fresh water, it's
not frozen, so it's got tobe above freezing, and I can deal
with temperatures above freezing. No.I mean, like, I was in
that cold water tank there for afew minutes or eight degrees and it was
(30:32):
starting to get unpleasant. And Inoticed because I actually had to spend longer
in there while we sorted out somestuff for the recording of the podcast.
So I spent sight long longer inthere than I normally would have done.
I lost some of the flexibility inmy legs, in my feet, my
toes, so I was stumbling slightlyas we got out in temperatures that would
(30:55):
I was happily working in in aT shirt yesterday when it was the air
temperature on land. So if you'reworking near water, either on a shore
or on rocks above it or somethinglike that, or more likely in a
boat, in a vessel of sometype, be prepared to enter that water
(31:15):
and what you're going to do afterwards, because if you enter the water and
the water temperature is even anything belowtwenty degrees eighteen degrees, it could quickly
and send you into a situation wherehypothermia is not just a real risk,
it is happening to you. Yourcore temperature can drop very very quickly.
(31:37):
You can lose dexterity in your fingers, you can lose the ability to think,
you can lose or at least toproblem solve. You can lose strengthen
your muscles. There's all sorts ofthings. We are breathing. We've got
the mammalian dive reflex, and youknow we can go into that, but
just think that if you enter thatcold water and it does not have to
be that cold, you are thenin a survival situation. If you enter
(32:04):
it unexpectedly, you're happily going alongdoing a thing, and now you're in
the water, then in many waysthat's worse because you haven't even got the
ability to mentally prepare for it.But if you're going somewhere where the water
is going to be cold or cooland there is a reasonable chance you could
(32:24):
end up in there, you shouldhave a management strategy for that before you
get there. So that strategy couldbe clothing, it could be spare clothing,
it could be what is attached toyour person. There are all sorts
of things around canoe journeys, andwe're going to talk about this in the
next episode and given away a littlebit what that's about, but how you
(32:46):
plan for that, but be preparedto enter that cold water and for you
then to be in a survival situationwhere you need to sort yourself out afterwards.
And if you're on your own,you're going to be already in a
(33:07):
position where it's harder to sort yourselfout, harder to fix that situation because
you are cold. So generally forif somebody has entered cold water and they've
become wet, and they have enteredcold moving water, particularly, then you
get them out onto the shore.You don't then keep them in their wet
(33:29):
clothing and add stuff on top.You get them out of the wet clothing
and get them dry as soon aspossible. If you're staying there in the
wet clothing, you are going tostill be losing heat, and you can
be pulling heat away from your bodyand crucially away from your core, and
(33:51):
send you into that state of hypothermiaquicker if you are wet. So get
them out of the water, getthem out of the wind, and we'll
talk about that. I keep teasingthis, but we'll talk about that shortly.
But get them out of the wetclothing and into dry clothing quickly.
(34:12):
The moisture is the real factor herethat you need to be aware of.
It's not just temperature. It's notokay, we'll make them warm and wet
rather than cold and wet. Okay, how about you make them warm and
dry. I keep emphasizing this.The rate at which the moisture pulls the
heat away from your body so muchhigher than dry clothing. Dry dry surfaces,
(34:34):
So manage that moisture, manage thatwater, manage that wetness as much
as the temperature. If you've onlygot one set of clothing with you and
that's all wet now, then youhave a problem. The whole point of
this podcast when we first started ita few years ago, was to counter
some of the stupid stuff we seeonline, some of the stupid stuff you
(34:55):
hear from other places, some ofthe stuff that's more about reinforcing a tough
man image or some other weird skewedthing about making things as uncomfortable for yourself
as possible, and instead push itback to what we know that works,
which is making good decisions and doinggood planning, make choosing good equipment,
(35:17):
doing the right things at the righttime, and some of those things you
had to have done weeks ago.And you can't just wait for a bad
situation to happen and then pull outyour magical piece of equipment that's going to
fix it all. If you enteredthat water without any way of getting warm
and dry soon after, it doesn'tmatter that you've got yourself out of the
(35:40):
river or out of the lake anddrag yourself onto the shore you're lying there
on a wet beach, in wetclothing, still losing heat, be losing
heat, maybe a little bit lessquickly than you were when you were in
the water, but you're still losingheat. Getting dry is really crucial here,
(36:01):
and that leads us on to thesecond part, which is a bit
I keep teasing wind. Any kindof moving air is going to be pulling
the little bit of heat that you'velost away from your body through the sweat,
which will make it pull away morequickly. But even in dry air,
on dry skin, rather, itwill pull that heat away from your
(36:22):
body much more quickly. Because imagineyou're standing there. You're standing there naked
in cool air, and your bodyis losing heat. It's losing heat from
what the surface you're touching, it'slosing heat from the breath coming out of
your mouth, it's losing heat throughradiation. But it is losing heat just
(36:43):
by warming up the area of airaround your body. So think about little
invisible suit you're wearing of heat beingpulled out, warming up a little zone
of air and next to your body. If you then were to grab that
little zone of heat and pull itaway from you, lost that heat and
you can't get it back. That'swhat wind does. It pulls this little
(37:05):
zone of warmth you have around youand pushes it off over there where it's
of no use to you. Soit's like being sucked away from you like
smoke. Insulating clothing helps reduce thisby keeping the little warm area of heat
next to your body under that clothing, under that insulation. But if you
(37:29):
take it off, the air canthen pull it away, or even on
a day without wind, if you'removing through it, you're leaving that heat
behind. So if you're mountain biking, or you're cycling or on a motorbike
or whatever, you're leaving even ona day without wind, you're leaving the
heat behind you. And you've probablyexperienced this when you go downhill and you
(37:50):
go down, you go or yougo faster, you feel cooler because I
think there was a nice breeze nowmoving. No, what's happening is all
of the heat that you're losing fromyour body. As soon as it leaves
your body, it's gone. It'soff there behind you somewhere. You're leaving
little zone of heat behind you.Slightly weird thing to think about, but
is kind it's an important concept toget that. If there's movement of air
(38:15):
around your body, whether it's throughwind or whether you're creating it. Because
you're moving through still air, you'releaving the heat behind or the heat's being
pulled away from you. So eventhough you might you might be losing heat
at a set rate because you've gotdry skin or wet skin or all that
stuff we've talked about, the factthat the air is pulling it away means
(38:37):
that that will be happening more quickly. So you may have heard the term
wind chill, and there are allsorts of wind chill calculators you can find
online, and I think we'll linkout to a couple, but they're all
a bit weird because it still doesn'tadequately reflect the temperature you'll feel in that
(38:58):
environment. So one windshield calculator weuse says that if the ambient temperature or
the air temperature around you is minuseighteen celsius and the zero wind, that's
about thirty minutes in that temperature beforeyou start to really develop any kind of
(39:19):
cold weather injury and for an averageperson, and really start to feel that
the effects of that cold in ameaningful way. But if you add a
fifteen mile an hour wind to thatminus eighteen temperature, or it's about twenty
four kilometers an hour, it's goingto feel like you were stood in minus
twenty eight celsius. Still there.That's all in dry conditions. If you
(39:45):
were wet in either of those conditions, so wet skin, minus eighteen celsius,
no air movement, you're in abad state. You're not going to
be lasting very long at all.If there was a fifteen mile an hour
wind and it's minus eighteen and you'rewet, I don't fancy your chances.
(40:06):
You've got to sort this situation outpretty quickly or you're going to die.
So all of that stuff I saidabout wet clothing being wet, wet through
sweat, wet through rain, wetthrough immersion into water, If you factor
in air movement on top of that, it starts to become a real issue.
(40:27):
And that's why it's still an issueeven though we're not in the depths
of winter now and here in theUK we didn't really have the depths of
the winter. Barely went blow freezing, but it was wet most days,
and it was windy most days,and I've had quite a few days this
winter where I've been working out inthe fields, working in the woodlands,
doing the other work we do,where I felt I'm on the edge of
(40:50):
mild hypothermia here because I'm wet andthe wind is pulling the heat away from
me. So I've had to choosemy clothing to reflect that, and I've
been having to balance out. Okay, i need a windproof layer of some
kind to stop that heat being pulledaway from me by the wind. But
if I'm working in a windproof layer, I'm going to get sweaty, so
(41:10):
I'll have wet clothing. So I'vehad to bring two or three different layers
out with me on different days toachieve different things. Managing body temperature in
wet conditions and in windy conditions,I think is much much harder than managing
body temperature in sub zero Arctic dryconditions. Scottish winter. Scottish wet winter
(41:38):
is a harder environmental I've found todeal with than high Himalayan mounting cold dry
air, because that moisture is areal factor, the wind is a real
factor, and together that is ahyperthermia factory. And I worry more about
(41:59):
hyperthermia. Don't do about frostbite,frost nip, those kind of things,
because the hypothermia creeps up upon youon days when you don't even think about
it because you're wet and it's slightlywindy. So the wind is an easy
one to talk about. And thefaster the wind, the more quickly it's
going to pull the heat away fromyou, and the more the colder you
(42:21):
will feel. Water is another factorwith this. You've got the water on
your skin pulling the heat away fourtimes faster. But and if you do
cold the cold plunge thing, oryou used to go swimming in cold water,
you'll know what this feels like.If you stay completely still in still
water in cold water, you caneventually feel like you're starting to acclimatize to
(42:45):
it, because what you're doing isbuilding up a little bubble of warm urh
not warm warmer water right next toyour skin. You're still losing heat into
that zone, and you will develophyperthermia eventually. If you stand there but
you've got this little warm area rightnext to your skin and it doesn't feel
quite as bad, and then swirlyour arms around and move around, you
(43:07):
will immediately feel much much colder,because what you're doing is the equivalent of
that wind pulling the heat away fromyour body. You're moving into colder water
all the time, and your bodyhasn't got a chance to heat up a
little layer next to it. It'sjust moving it around all the time.
So that's why moving water will alwaysfeel colder than completely still water, or
(43:34):
if you're moving through the water.So if you stand, if you float
completely still, it's submerged in water, the water doesn't move, you don't
move, you will feel warmer thanif you start swimming through it. You
might build up some heat inside andyour core through the exercise of swimming,
and that will have its own effect, But immediately you will feel colder because
(43:54):
you've started moving through the water,or if the water starts moving around,
or if you're in a river,that heat is being pulled away from you
straight away. So the movement ofthat little warm zone next to your body
from either wind or water in theoutdoors is going to be another factor.
(44:15):
So these are the two things.If your body gets wet, it will
lose heat much more quickly if yourbody is an environment where the heat is
being pulled away from you. Butby either airflow or water flow, you
will lose heat a lot more quickly. If you are wet and an environment
where there is airflow around you,you are going to lose heat very quickly.
(44:39):
If you are in cold water andit is moving or you're moving through
it, you will lose heat veryquickly. So you've got to be aware
of those two things, moisture movement, and that's why it's taken a whole
episode to go through this, andit's a really subtle thing to get your
(45:02):
head around because how you deal withit, how you manage it, is
going to be very dependent on whatyou're doing, what the temperature is,
what you're going to be doing next, what equipment you have with you,
how you're using that equipment. Waymore than we can go into with this,
this is part of good outdoor skills, which you've got to go out
(45:23):
and make mistakes and make soft mistakes, makes lots of little mistakes and get
cold and uncomfortable in a way thatyou can recover from and that where you
can do safely and learn what happens. We could talk about, as I've
talked about a lot in this episode, walking up hill with a rucksack,
but I could do a whole episodeon managing your body for moisture and air
(45:45):
temperature and moving air when mountain bikingversus road cycling. Do another one for
swimming, do another one for canoeing. All of these things, all of
these activities in these different environments.You've got to manage yourself else. But
take that away colder temperatures hypothermia.Think about the moisture on your body and
(46:08):
how that is held there, andwhat's happening with that moisture, how it
got there, what you're doing tokeep it out, what you're doing to
get rid of it, what you'redoing to prevent it happening again, what
you're doing to stop the effects ofthat moisture by changing into other layers.
And then the movement of things aroundyour body, air or water, those
two factors. If you can managethose and think about those, that is
(46:30):
going to be your best chance atpreventing hypothermia. But remember, hypothermia is
different to frostbite, it's different tofrost nip. It is a completely separate
designation hypothermia. Drop core temperature dropsblow thirty five and then you have mild,
moderate, and severe. That isthe takeaway. It's moisture management,
(46:52):
wet management, water management, whateveryou want to call it, and movement
management. What's that window to you? How much in the wind are you?
What are you doing to reduce theeffects of it? How prepared are
you for it? Or moving waterversus still water. I don't think I
can break it down any more thanthat without giving hyper specific examples. So
(47:15):
now we're going to move on totalking about things in the after show.
So thank you for listening, andkeep an ear out for that next episode
because it really ties into this oneand it comes up with some really practical
examples of what happens when this doesn'tgo quite as well as you hoped.
Thank you for listening to this episodeof Modern Outdoor Survival from Original Outdoors.
(47:36):
If you go along to Modern OutdoorSurvival dot com. There you will find
links to all of the content andeverything we've talked about in this episode,
plus links to all of the previousepisodes and the show notes for those episodes.
You will also find links to ourPatreon page where you can become a
supporter of the show and get ridof all of those pesky adverts and access
(47:58):
to bonus extra content and stuff thatthe public never gets to hear, and
behind the scenes stuff and a fewother things that are hidden away within there.
You've also got our Instagram account whichis at Modern Outdoor Survival. We
don't post on their huge amount,but we do post photos from things that
we talk about in the episodes.You will also find a link to our
(48:20):
discord platform where we have a groupfor Original Outdoors as a wider community.
There you can meet and talk topeople and discuss things, but all with
the anonymity of an early two thousand'sforum or bulletin board. It's a nice
retro way of going about things.I'm going to leave you now with our
three principles of Modern outdoor Survival andthey are Number one, make good decisions
(48:46):
at the right times. Number two, prioritize training over shiny new equipment.
Number three remember Instagram is not yourtraining provider. Five
Popular Podcasts
NFL Daily with Gregg Rosenthal
Gregg Rosenthal and a rotating crew of elite NFL Media co-hosts, including Patrick Claybon, Colleen Wolfe, Steve Wyche, Nick Shook and Jourdan Rodrigue of The Athletic get you caught up daily on all the NFL news and analysis you need to be smarter and funnier than your friends.
On Purpose with Jay Shetty
I’m Jay Shetty host of On Purpose the worlds #1 Mental Health podcast and I’m so grateful you found us. I started this podcast 5 years ago to invite you into conversations and workshops that are designed to help make you happier, healthier and more healed. I believe that when you (yes you) feel seen, heard and understood you’re able to deal with relationship struggles, work challenges and life’s ups and downs with more ease and grace. I interview experts, celebrities, thought leaders and athletes so that we can grow our mindset, build better habits and uncover a side of them we’ve never seen before. New episodes every Monday and Friday. Your support means the world to me and I don’t take it for granted — click the follow button and leave a review to help us spread the love with On Purpose. I can’t wait for you to listen to your first or 500th episode!
Dateline NBC
Current and classic episodes, featuring compelling true-crime mysteries, powerful documentaries and in-depth investigations. Follow now to get the latest episodes of Dateline NBC completely free, or subscribe to Dateline Premium for ad-free listening and exclusive bonus content: DatelinePremium.com