Cold Weather and it's associated risks. *UPDATED* 2010-08-23

[A.C.E.]

This post will be continuosly updated with more info. All updates will be accompanied by a bump containing the new info that I add to the original post.

Please feel free to post criticism and suggestions in this thread. I will check any new info and then edit it into the OP.

Of course, any discussion related to cold weather is welcome. I'll do my best to answer any questions.


First of all, Frostbite.
Frostbite is when a small area of your skin turns white and cold to the touch. What's happened is that all the blood has left the skin causing it to become white. At early stages this is not dangerous in its own. It will however turn dangerous VERY fast if left untreated. The skin can freeze wich will damage the cells and it will get damaged very easily.

The treatment consists of warming the skin very gently. Use your naked hand and place it over the damaged area. Absolutely no rubbing! Be very gentle. If an entire hand/foot is affected it can be warmed by submerging it in bodytempered water, no warmer than 37C. The skin will be numb and could get burned very easily as it has no way to defend against the heat. The best place to warm a foot or hand is someone elses armpit or groin, this is how you find out how your true friends are . Keep warming until it no longer feels cold to the touch and all feeling has returned to the skin. DO NOT RUB WITH SNOW!!!

If the skin has turned black the condition is VERY serious and you'll need qualified medical attention to save the limb. Don't let it go that far.

Be aware that an area that has suffered frostbite in the past will often have permanently reduced circulation and will therefore get frostbite again more easily.

Usual places to suffer frostbite includes the ears, nose and cheekbone. Something to look out for is that some models of rifles (AK5 for instance) will place the shooters nose and cheek against or very close to metal parts of the gun, especially when the shooter is lying down. These areas are very prone to getting frostbite during cold weather. I've seen it several times in the Swedish army. Putting insulating tape on the gun can help to prevent this. If you must wear eyeglasses outside during cold weather, be aware that a metal frame will transport heat from (thus cooling) your skin. If you see well enough, take your glasses off while outside.


Hypothermia.
Hypothermia is when the bodytemp has dropped below normal level (normal is 36-37.5C, <35C and you're by definition hypothermic), causing the body to limit bloodflow to the limbs. It may be caused by illness, poisoning or exposure. Often a combination of these will worsen the symptoms very quickly. It's possible to develop hypothermia even in relatively mild weather. Especially if you are exposed to wind in combination with wet clothing.

The patient will often be unable to help himself. Apathy and sleepiness are very common symptoms and you may have to force the patient to cooperate. The patient should be kept conscious if at all possible.
RULE OF THUMB: If a person is trembling, it is not very serious. Force him/her to move around and drink something warm. If the person is no longer trembling he/she can longer help himself and will need help if he/she is to have any chance to make it.

Treatment consists of gently raising the patients temperature, VERY SLOWLY. If the patient is awake and conscious give him something warm, NOT hot, to drink. Remove any wet clothing from the patient and let a healthy person warm him/her with their own body. Ideal is to squeeze together in a warm sleeping bag but wrapping in some blankets will work as well. KEEP THE PATIENT AWAKE.

Be very careful when bringing the patient Directly into a heated room or tent. The bodys defense agianst hypothermia is to limit the amount of blood circulating in and out from the core of the body. The warm blood will be kept around the organs to keep the core-temperature stable. Raising the temp around the body to quickly can fool the system and allow cold blood into the bodys core. This can cause a type of shock wich may kill the victim. Keep close watch and be prepared to start CPR as in the worst case scenario the victims heart could stop. For the same reason, it is very dangerous to elevate the limbs of the patient. Try to move the patient as little as possible.

Body temperature and you:
36-37.5C Normal bodytemp. This is what you want to have.
MODERATE HYPOTHERMIA
35C Severe shivering, reduced motorcontrol, reduced judgement and decision making ability, apathy.
33C Reduced or no shivering, unability to use hands, confusion.
SEVERE HYPOTHERMIA
30C No shivering, unable to walk, severly confused.
28-30C Weak pulse and breathing, risk of heart arrythmia (spelling?) or fibrillation.
25-27C Unconsciousness, victim may appear dead.

Source: Swedish Army winter warfare manual, "Vintersoldat" M7742-112112 page 25.

WINDCHILL
As most aleady know, moving air cools you, this phenomenon is called Windchill. Below is a chart showing how much colder it gets for every mph. of wind. Credit for this chart goes to US Search and Rescue Task Force. http://www.ussartf.com



As you can see, even relatively mild wind greatly decrease the felt temperature.
This is why it is so important to have good shelter from the elements during winter. As long as there is no wind, a person wearing suitable clothes can endure quite cold weather. Around -30C (-20F) is cold but still bearable. The chart shows this temperature as just bordering on "increased danger".

Now, if the wind goes up to just 10mph. (not very much) the experienced temp drops to a whopping -43C (-46F). If you work up a sweat in this temperature and are unable to dry your clothes, this may very well kill you. I cannot stress enough how important it is to keep dry if at all possible. If you know that you will be working hard outside, try to keep a dry change of clothes ready for when you are done. Make sure you adjust your clothing to the weather.

Don't overdress, beeing a little cold before you start working is annoying, but working in to much clothes and getting sweaty is really dangerous. Adjust your clothing as you work up a temperature. Ventilation is key, open your jacket and unzip your fly to vent excess heat. As soon as you take a break, remember to put on a warm hat and jacket to conserve your bodyheat and prevent your sweaty clothes from freezing.

If you know that you will be going in and out of warm buildings a lot make sure to remove all snow from your clothes and shoes before going inside. If you don't the snow will melt and you'll get wet.

TRENCHFOOT
Trenchfoot (aka. jungle foot, jungle rot, fat foot) is a very serious condition caused by damp, cold and unsanitary conditions. Unlike frostbite, the temperature does not need to be below freezing, it is still a risk in as high as 16C (60F). Early symptoms include numbness, itching or tingling sensations and your feet turning red or blue. Later symptoms include decaying odor, skin turning white and waxy, blistering, necrosis and gangreene.

Treatment in the field is almost impossible, hospitalization with long convalescence is very common. It is also quite painful. Luckily, prevention is fairly uncomplicated.

Preventing trenchfoot: Keep your feet dry, the best way is to change socks regularly. Move around to keep circulation up, avoid wearing tight shoes that may restrict bloodflow. Do not sleep with your shoes on if it can be avoided. Do not rub any salve on the feet.

Treatment: Keep the victims feet dry and warm at all costs. Any sores or blisters should be kept clean to minimize risk of infection. Do not stand or attempt to walk. The tissues on the foot will be very sensitive and walking around can cause severe damage. Do not underestimate the seriousness of this condition, get medical help. Chances of recovery are good IF the victim gets to a hospital.


PREVENTING INJURIES RELATED TO COLD
The on thing all cold related problems have in common, is that prevention is far easier than treatment. Below you will find a list of things you should always keep in mind when working in a cold environment:

1. Check each other. Look at your buddy, does he have white spots in his face? Talk to him, is he responsive and alert? Take off your gloves and inspect your hands.
2. Keep dry. Change your socks as often as you can. If you are hiking or skiing once every hour is a good interval. The "Short Break" and "Long Break" will be described below.
3. Hydrate. Drink much more than you think you need. You'll need as much (or more) water during a really cold day as during a really hot. Bring a thermos bottle with boiling hot water, refill it whenever possible. See "Long Break" below.
4. Eat. Your body needs fuel to keep warm. See "Long Break" below.
5. Keep active. True warmth comes from within. Staying still will only cool you further.




TAKING A BREAK
There are two types of breaks, the long and the short. The main purpose of the short break is to hydrate and adjust equipment. Not rest. The main purpose of the long break is to refuel and refill. Again, NOT REST.


The Short Break
This break takes 5 min. You should take a short break every hour while on the move. If needed the short break can be as much as 15min. to allow for adjusting or repairing equipment. NO LONGER!

What you do:
1. Stop! Take of your backpack.
2. Put on your warm jacket or coat. It should be packed in such a way that you can get it in <10sec. It should be big enough to fit over any LBE or "tactical" stuff your wearing.
3. Sit down! Sit on a pad or on your pack, never on the ground/rock/log/whatever. Isolate and insulate yourself from the ground.
4. Drink warm liquid. Water or tea is best. You should keep boiling hot water in a thermos bottle, take some hot water in a cup and then dilute it with snow or cold water until it is pleasant to drink. Never keep anything but water in your thermos, you might not be able to wash it.
5. Change socks. Putting on dry socks when your feet are cold and tired is as close as you'll get to heaven in this life. You could also change the insoles of your boots at this time. In fact, I warmly recommend doing so. REMEMBER TO CHECK YOUR FEET FOR FROSTBITE.
6. Check your gear. Then check your buddy's gear. Then see if anyone needs any help. This is a good time to check your buddy for signs of frostbite. Remember to check your hands and feet as well. COLD FEET AND HANDS ARE PINK, THIS IS NATURAL. FROSTBITE IS A WHITE SPOT, LOOKS ALMOST LIKE WHITE PAINT ON THE SKIN.
7. Stand up. Make sure you haven't lost anything in the snow.
8. After 4min. 30sec. it's time to take off your jacket and put it in your pack.
9. At 4min. 45sec. Put your backpack on. MAKE SURE YOU DIDN'T DROP ANYTHING IN THE SNOW.
10. At 5min. leave.

Keep track of the time. You should start changing socks within 90sec. If you are in a group, have the group leader notify the group every 1min.
If someone has a problem that takes more than 5min. to fix, everyone not helping should get up and start moving around after 5min. This is very important, it's to preserve your bodyheat.



The Long Break
This break takes longer, up to one hour.

What you do:
1. Stop! Take of your backpack.
2. Put on your warm jacket or coat.
3. Immediately start melting snow and boil water. Work in pairs with a buddy. Buddy 1: Melt snow-> boil the water-> refill your thermos. Buddy 2: Make food.
4. While water is boiling, change socks, check gear, check buddy, check rest of group.
5. When you have eaten and filled your thermos with boiling water. Report to the group leader that you and your buddy are done.
6. When everone is done, depart immediately. If you have to wait for someone, move around to keep warm. Do not take of your warm jacket until 30sec. before leaving. Conserve your bodyheat.



OTHER RISKS
Any wound or injury will heighten the chance of developing frostbite/hypothermia. Especially if there is bloodloss involved. Keep wounds and injuries as warm as possible to prevent this.

Desinfectants that contain alcohol will not freeze at the same temperature as water. Do not use cold alcohol to clean wounds as it could be well below zero and still liquid. This can cause frostbite by itself. The same goes for alcogel and similar skin desinfectants. As they evaporate they cool the skin even further. Of course, the same thing goes for diesel, petrol and other fuels as well. any liquid that doesn't freeze is a major hazard.

Great care must be taken when refueling during extreme cold, supercool liquids can freeze your skin in seconds. A pair of rubber gloves, either insulated or pulled over another pair of gloves is a good way to avoid skin contact, simply wearing thin rubber gloves will not help much as they have almost no insulation at all.


While on the subject of petrol, remember also that it is much more prone to exploding in cold weather than in warm.

THE BEST WAY TO PREVENT FROSTBITE IS TO CHECK EACH OTHER REGULARLY. If you are skiing or hiking with a comrade, look at each others faces every few minutes. Any white spots indicate frostbite and should be treated immedietly. Be extra careful if wearing glasses as the frame will transport heat away from the skin.

This post will be updated, criticism is very welcome, either by answering the post or sending a PM.

[JIM]

Hi A.C.E.

Nice post you made here. I have some additions:


- A normal body temperature varies from 36 to 37.5 degrees Celcius. If the temperature drops below 35 degrees, then you're hypothermic.

- Body temperature should be measured rectally in a hypothermic patient. Axilair, oral and tympanic methods are NOT relieable!

- A victims heartbeat should be determined in the the carotic, radial and groin. Bloodvessels constrict, so when there isn't a radial pulse, that doesn't mean there is no heartbeat.

- Always start CPR on a hypothermic victim, unless death is obvious (like a decapitation). He's not dead untill he's warm and dead!

- You mentioned that only people that are consignous should be given warm drinks. You're correct about that, I just wanted to add that the reason that unconsignous people don't get oral liquid/food is because they have a large risk on a gag-reflex / aspiration.

- And I respectfully disagree with you on not placing a victim in a warm inviroment. As long as it get's warmed slowly it should be fine. EMS does that too and in the ER, they use special blankets which circulate warm air in them. Also, medical professionals can give warm IV-solutions or even place 2 thorax-drains which are used to flush the thorax with warm saline.


Finally, allthough frostbite often looks very bad, they do have the possibility to heal pretty good.

[A.C.E.]

I didn't want to go into advanced stuff like exact degrees and such before checking to make sure. The post will be updated with charts on this and some other things like how to calculate windchill and also some pics as soon as I get home. (Probably tomorrow night GMT+1)

- Always start CPR on a hypothermic victim, unless death is obvious (like a decapitation). He's not dead untill he's warm and dead!

QFT We were told that noone is dead until a doctor comes along and says so. Until then, CPR.

- And I respectfully disagree with you on not placing a victim in a warm inviroment. As long as it get's warmed slowly it should be fine.

You're right. I was a bit unclear on this. Placing a victim in a reasonably warm room is ok. What IS dangerous is to heat the victim quickly, like bringing him or her directly from the cold into a tent with a large woodstove or placing him/her indoors next to a heater of some sort. I'll change this right away.

EMS does that too and in the ER, they use special blankets which circulate warm air in them. Also, medical professionals can give warm IV-solutions or even place 2 thorax-drains which are used to flush the thorax with warm saline.

Unfortunately, I have neither in my FAK. (Perhaps for the best. ) And even if I did I have no idea how to safely place an IV, much less a thorax-drain.

[A.C.E.]

Bump

Updated the original post with a windchill chart, as well as some general cleaning up.

Hopefully it won't be 2years til the next update.

[macandcheese]

SUPER helpful post; thanks, ACE!

I'm about to train a handful of new lifeguard cadets, and some of this very info is in the lesson plans. Good stuff.

[the_alias]

tagged.

Great stuff ACE

[A.C.E.]

Thanks everyone.

I'll continue to update with more stuff as I have time to write it down. New text will be marked at least until the next update. I'll also bump whenever I add something.

After posting this I'll update the section at the end with some stuff I forgot last time. So consider this a bump for update as well.

<EDIT> Update complete.

[Krustofski]

This is a very, very, very good writeup.

About moving hypothermic patients around, especially after accidents involving breaking through the ice into a frozen body of water, I'd like to add something I mentioned before in this forum:

I know that this is dumb advice, but what about the advice that a hypothermic person should be placed in a lukewarm (almost cold) shower and to gradually increase the temperature when the hypothermia symptoms lessen? Is that true or have I been listening to the wrong people?

In itself not a bad idea, as gradually increasing temperature is a common method of treating hypothermia. However, you're setting you patient up for something that is called "Bergungstod" (literaly "Rescue work death") in German. I don't know if there's an English translation for the term, but basically it means the patient is going to die because you flailed his limbs around too much.
Moderate and severe stages of hypothermia lead to peripheral vasoconstriction, which means a centralization of blood flow. Basically this ensures inner organs get their share of nice warm blood, while the extremities don't. If you pull an unconscious but alive patient out of the frozen lake, don't, I repeat, don't lift his arms or legs above the level of his center of mass. Because the limbs where cut off from blood flow to save the vital organs, the blood which actually is in them, is a few degrees colder than the core temperature. If this blood flows back into the core, it will worsen the condition. In fact, the patient might die on the spot.

So, long story short, if the patient is suffering from severe Hypothermia, down to the point of loosing consciousness, don't move him around to get him under the shower. If you can help it, at least. If the alternative is "leave him out in the freezing cold for six hours", then I'd give it a try

In cases of mild hypothermia, i.e. "blueish, shivering a bit, but can still move his toes", yeah, get the patient under the shower, why not.


ETA: Disclaimer: I'm not a physician, just a medic, yadda yadda.

The centralization of blood flow and cold limbs have allready been mentioned, I just wanted to point it out again.

As for the CPR on hyphothermic patients, I was told that "No one is dead until warm and dead."[1]


[1]: Iyer, Rajkumar, Sadasivan, Bruce, Gilfillan: No one is dead until warm and dead. The Journal of thoracic and cardiovascular surgery. 2007 Oct; 134(4):1042-3.

[A.C.E.]

Thank you.

I remember reading that post before. I'll edit and add the bit about not elevating limbs to the original post. This post vill be updated when done.

<EDIT> Done! Bump for update.

[A.C.E.]

Bumping with update again. This info will be edited into the original post as well.

Body temperature and you:
36-37.5C Normal bodytemp. This is what you want to have.
MODERATE HYPOTHERMIA
35C Severe shivering, reduced motorcontrol, reduced judgement and decision making ability, apathy.
33C Reduced or no shivering, unability to use hands, confusion.
SEVERE HYPOTHERMIA
30C No shivering, unable to walk, severly confused.
28-30C Weak pulse and breathing, risk of heart arrythmia (spelling?) or fibrillation.
25-27C Unconsciousness, victim may appear dead.

Source: Swedish Army winter warfare manual, "Vintersoldat" M7742-112112 page 25.

TRENCHFOOT
Trenchfoot (aka. jungle foot, jungle rot, fat foot) is a very serious condition caused by damp, cold and unsanitary conditions. Unlike frostbite, the temperature does not need to be below freezing, it is still a risk in as high as 16C (60F). Early symptoms include numbness, itching or tingling sensations and your feet turning red or blue. Later symptoms include decaying odor, skin turning white and waxy, blistering, necrosis and gangreene.

Treatment in the field is almost impossible, hospitalization with long convalescence is very common. It is also quite painful. Luckily, prevention is fairly uncomplicated.

Preventing trenchfoot: Keep your feet dry, the best way is to change socks regularly. Move around to keep circulation up, avoid wearing tight shoes that may restrict bloodflow. Do not sleep with your shoes on if it can be avoided. Do not rub any salve on the feet.

Treatment: Keep the victims feet dry and warm at all costs. Any sores or blisters should be kept clean to minimize risk of infection. Do not stand or attempt to walk. The tissues on the foot will be very sensitive and walking around can cause severe damage. Do not underestimate the seriousness of this condition, get medical help. Chances of recovery are good IF the victim gets to a hospital.

[Sealegs]

Swedish Army regulation trench foot treatment anno 1719



Keep those feet dry, warm and high! And never ever sleep with your boots on in the winter time. Whenever you think about not changing your socks or keeping your boots on, think about THE SAW!

Mkt. bra post A.C.E.! [Very good post A.C.E.!]-translation from bork bork speak.

[A.C.E.]

I did my military service in the northernmost parts of Sweden. First time we pitched a tent it wass -36C. For 15 months I had the dangers of cold weather beaten into my thick head every day. And it worked, not a single case of hypothermia. The worst we ever saw in my unit was white spots on the cheeks, courtesy of the metal and plastic furniture on the Swedish AK5.

[Sealegs]

I22 or I19? Same same but a few of my friends are kind of happy about I22 being shut down.

The fear of "repmånad" can do that to you

[P4 for me but I too know the suck of Kiruna and Arvidsjaur.]

[A.C.E.]

I22 or I19? Same same but a few of my friends are kind of happy about I22 being shut down.

The fear of "repmånad" can do that to you

[P4 for me but I too know the suck of Kiruna and Arvidsjaur.]

PM sent.

[A.C.E.]

I feel bad for turning this into a chat thread. So, without further ado.

**BUMP FOR UPDATE**

PREVENTING INJURIES RELATED TO COLD
The on thing all cold related problems have in common, is that prevention is far easier than treatment. Below you will find a list of things you should always keep in mind when working in a cold environment:

1. Check each other. Look at your buddy, does he have white spots in his face? Talk to him, is he responsive and alert? Take off your gloves and inspect your hands.
2. Keep dry. Change your socks as often as you can. If you are hiking or skiing once every hour is a good interval. The "Short Break" and "Long Break" will be described below.
3. Hydrate. Drink much more than you think you need. You'll need as much (or more) water during a really cold day as during a really hot. Bring a thermos bottle with boiling hot water, refill it whenever possible. See "Long Break" below.
4. Eat. Your body needs fuel to keep warm. See "Long Break" below.
5. Keep active. True warmth comes from within. Staying still will only cool you further.




TAKING A BREAK
There are two types of breaks, the long and the short. The main purpose of the short break is to hydrate and adjust equipment. Not rest. The main purpose of the long break is to refuel and refill. Again, NOT REST.


The Short Break
This break takes 5 min. You should take a short break every hour while on the move. If needed the short break can be as much as 15min. to allow for adjusting or repairing equipment. NO LONGER!

What you do:
1. Stop! Take of your backpack.
2. Put on your warm jacket or coat. It should be packed in such a way that you can get it in <10sec. It should be big enough to fit over any LBE or "tactical" stuff your wearing.
3. Sit down! Sit on a pad or on your pack, never on the ground/rock/log/whatever. Isolate and insulate yourself from the ground.
4. Drink warm liquid. Water or tea is best. You should keep boiling hot water in a thermos bottle, take some hot water in a cup and then dilute it with snow or cold water until it is pleasant to drink. Never keep anything but water in your thermos, you might not be able to wash it.
5. Change socks. Putting on dry socks when your feet are cold and tired is as close as you'll get to heaven in this life. You could also change the insoles of your boots at this time. In fact, I warmly recommend doing so. REMEMBER TO CHECK YOUR FEET FOR FROSTBITE.
6. Check your gear. Then check your buddy's gear. Then see if anyone needs any help. This is a good time to check your buddy for signs of frostbite. Remember to check your hands and feet as well. COLD FEET AND HANDS ARE PINK, THIS IS NATURAL. FROSTBITE IS A WHITE SPOT, LOOKS ALMOST LIKE WHITE PAINT ON THE SKIN.
7. Stand up. Make sure you haven't lost anything in the snow.
8. After 4min. 30sec. it's time to take off your jacket and put it in your pack.
9. At 4min. 45sec. Put your backpack on. MAKE SURE YOU DIDN'T DROP ANYTHING IN THE SNOW.
10. At 5min. leave.

Keep track of the time. You should start changing socks within 90sec. If you are in a group, have the group leader notify the group every 1min.
If someone has a problem that takes more than 5min. to fix, everyone not helping should get up and start moving around after 5min. This is very important, it's to preserve your bodyheat.



The Long Break
This break takes longer, up to one hour.

What you do:
1. Stop! Take of your backpack.
2. Put on your warm jacket or coat.
3. Immediately start melting snow and boil water. Work in pairs with a buddy. Buddy 1: Melt snow-> boil the water-> refill your thermos. Buddy 2: Make food.
4. While water is boiling, change socks, check gear, check buddy, check rest of group.
5. When you have eaten and filled your thermos with boiling water. Report to the group leader that you and your buddy are done.
6. When everone is done, depart immediately. If you have to wait for someone, move around to keep warm. Do not take of your warm jacket until 30sec. before leaving. Conserve your bodyheat.

[Treacle_Man]

First, amazing post. People like you are the reason I rarely post in the First Aid thread, makin' me look even dumber than I am

Second, a question I'm hoping you didn't already address and if you did my bad. I don't live in anywhere near as cold an environment as Sweden but I do like to do some winter camping when it gets kinda cold. I was wondering if there was a specific temperature range in which you are: not, maybe, likely or definitely going to get frostbite?

I'm hoping that I know what I'm talking about when I say that exposed body parts are more prone to frost bite (aka face ears like you said). How much less of a chance of getting frost bite on parts of the body that are covered but still, I don't know, a little more exposed than normal? I'm thinking mostly about hands in a glove (not a mitten) or boots with socks that arent insulated well enough etc.

again, thank you, great post. I will be tuning in in the future

[A.C.E.]

I was wondering if there was a specific temperature range in which you are: not, maybe, likely or definitely going to get frostbite?

How much less of a chance of getting frost bite on parts of the body that are covered but still, I don't know, a little more exposed than normal? I'm thinking mostly about hands in a glove (not a mitten) or boots with socks that arent insulated well enough etc.

This turned out to be another wall of text, if you (or anyone else reading this) are thinking OMG TL;DR. Just read the bold parts, the rest is me going on a long rant against cotton (and some other random bits).

Frostbite is a bit tricky to predict. There are many individual factors that apply, generally speaking, people with better circulation are less prone to getting frostbite. Smokers, unfit people and the elderly are high risk groups. Very skinny and very obese people are also at an elevated risk. Also, areas of your body that has suffered frostbite before are likely to get it again.

My best answer to your first question is: Look at the windchill chart in my OP. Green numbers are low risk, yellow are medium risk and red are high risk.



Second question.

Proper clothing, kept dry, will offer good protection. Water, including sweat is your enemy. Socks and gloves made from the wrong materials will keep the water (sweat) trapped around your skin where a proper material will transport it away and dry up quicker.

I suggest wearing moisture wicking gloves and socks (and everything else too for that matter) closest to your body. Absolutely never cotton. On top of this first layer you want something that absorbs the moisture without loosing it's insulating propertes. Wool is by far the best.

Your boots basically don't need to insulate at all, that's what socks are for. I wear leather boots with no insulation all year around. I just have a size larger for winter to fit an extra pair of socks in there. Just make sure to change your socks often. If you know you have shitty boots and socks there is still hope. Find a newspaper, using your insoles as a template, cut out insoles from the newspaper, use the full thickness, (PROTIP, staple all the pages together with one or two staples) and put this improvised insole UNDER your ordinary one. The paper will absorb moisture from your socks and insoles and can be replaced easily. In a pinch paper towels will work as well, but they make a mess in your boots.

Operating in wet socks, gloves and boots WILL mess your day up. Your feet sweat over a tablespoon every day, even if you aren't working at all. This needs to be transported away from your skin as quickly as possible. The easiest way to accomplish this is to change socks. Same thing goes for your hands, but they sweat even MORE. Change your gloves as often as you can.


What I'm getting at with this wall of text is that you shouldn't have to worry IF you're wearing good gloves and change your socks often. Avoid cotton like the plague, you might as well dress in wet towels. Keep your hands dry, dry hands rarely get cold.


I have a method for keeping my hands warm when working, it works even in extreme cold.

First, put on a pair of thin knitted WOOL gloves. 100%wool or gtfo. Then put on a pair of thick rubber gloves, like army NBC gloves or thick chemical resistant ones. They should NOT be tight or elastic, you want them to fit well without constricting your bloodflow.

Wear this setup while doing hard labour and your hands will stay warm. What happens is that your warm sweat will be trapped in the wool gloves where it helps keeping your hands warm. The rubber gloves will keep melting snow from washing the warm sweat out of your gloves, so as long as you're working and producing more warm sweat your hands will be kept warm. When you are done, take the gloves off, wring the rubber ones inside out and wipe them dry. Dry the wool gloves in some suitable way.

If you start feeling cold while working, take the gloves off immediately and check your hands for signs of frostbite. Change the wool gloves if they are soaked. Usually though, your hands will feel very hot the entire time.

[Treacle_Man]

My best answer to your first question is: Look at the windchill chart in my OP. Green numbers are low risk, yellow are medium risk and red are high risk.

Well, seeing as how I rarely go into the wild without at least some form of decent weather protection (usually super overkill, this is ZS after all), in my area I will rarely have to worry about frostbite at all according to this chart . doesn't mean I still won't be careful though. I don't know if I've even been in any weather below 0 (not counting wind chill)... I'm a disgrace to my Swedish roots I know Better go eat some köttbullar and bruna bönor to make up for that.

(PROTIP, staple all the pages together with one or two staples) and put this improvised insole UNDER your ordinary one. The paper will absorb moisture from your socks and insoles and can be replaced easily. In a pinch paper towels will work as well, but they make a mess in your boots.

I'm totally trying this, boot size permitting of course

Thanks again for the info, I'll be trying some of your advice out in a couple months when it gets cold-ish

ninja edit - have you heard anything about urine / urination affecting how your body handles the cold? I have heard that holding it in diverts energy from keeping your body warm to keeping the urine warm so it wont grow harmful bacteria... not sure how much truth this hold so I figured I would ask.

[Sealegs]

ninja edit - have you heard anything about urine / urination affecting how your body handles the cold? I have heard that holding it in diverts energy from keeping your body warm to keeping the urine warm so it wont grow harmful bacteria... not sure how much truth this hold so I figured I would ask.

You have to urinate and rehydrate, make sure you drink warm. Every time you fry something like fish, or cook something, save the broth and/or warm snow into hot water bullion without washing the pot out. Pour in thermos, that you have an insulation for sleeve and wear inside the jacket. Disgusting but energy saving.

On peeing at night:
Carry a scrunched up .5l PET bottle in your bag. Inflate when you go to sleep. Use for peeing and then hold as a warm water flask. Disgusting but works.

[A.C.E.]

I can't remember exactly how the process works, but a part of your body's defense against cold is to increase your metabolism. Your kidneys are made to work harder, producing more urine. It is because of this you need so much fluid during winter.

Not urinating properly disrupts this process, hindering your body in it's efforts to keep warm.

Not hydrating properly also causes your body to loose heat. When dehydrated your muscles can't work properly and as a result, your body produces less heat.

[Mister Dark]

Excellent posts! With colder weather approaching, I hope everyone here takes the time to read this. This isnt just valuable information for our northern brothers and sisters - hypothermia can kill even down here in the south. Years ago before I got smart, my car broke down one december night. In the two hours before the wife showed up to get me, I got so cold I could barely open the car door! I was shivering for another 15 minutes after she picked me up. I didnt realize til later how close I was to serious, serious trouble. And that was on a night that was in the high-30's, just a few dozen miles from home, on a fairly busy highway.

(dont get me started on how many state troopers drove past without even slowing down)

[TacAir]

I can't remember exactly how the process works, but a part of your body's defense against cold is to increase your metabolism. Your kidneys are made to work harder, producing more urine. It is because of this you need so much fluid during winter.

Not urinating properly disrupts this process, hindering your body in it's efforts to keep warm.

Not hydrating properly also causes your body to loose heat. When dehydrated your muscles can't work properly and as a result, your body produces less heat.

Some additional bullet points:

It is called "cold Dieresis" - the blood in the extremities flows back to the core. Too much blood and the kidneys filter out the water to reduce volume - so you piss a lot.

Not mentioned - NO Coffee or tea (unless you will be in a warm area for a minimum of 30 min) - the caffeine acts as a vasoconstrictor and can contribute to frostbite. Certain prescritption drugs also have this effect.

Earlier mention was made of running warm liquid through a pt thorax - the term is “peritoneal lavage” - an older technique also used when intra-abdominal bleeding (hemoperitoneum), usually secondary to trauma, was suspected - now ultrasound is in use.

A hypothermic pt and CPR. This paper may be of interest to those in a hospital setting. In the field, remember the arrival of cold blood from the extremities may cause enough shock to stop a heart.

You can check the USCG for additional information on "Mammalian Diving Reflex" - important when treating drowning victims.

[maldon007]

Awesome thread, great read. I live in cen. Fl, so a lot of it does not apply here... But if I lived in a cold climate, I would probably know most of this stuff. So being a cold weather newb, this info seems all the more important, since I do visit cold areas fairly often.

Would some specific recomendations for gloves & other gear (as in brands/models) be out of line in this thread?

[TacAir]

Awesome thread, great read. I live in cen. Fl, so a lot of it does not apply here... But if I lived in a cold climate, I would probably know most of this stuff. So being a cold weather newb, this info seems all the more important, since I do visit cold areas fairly often.

Would some specific recomendations for gloves & other gear (as in brands/models) be out of line in this thread?

No.

Simple (and heavy answer) wool.

I'll confess to a Eddie Baur down parka when it is REALLY cold - say -20 or colder.

But I was just fine in most of the issue junk (well and my EB) at -60. The VB boots can be a killer, so learn to swap out your socks every time you stop. Nowadays I wear Caribou pacs - those Canadian leather/rubber boots with the felt liners. I carry a second set of liners and additional felt 'soles' for when they get damp form snow that sneaks in and melts.

The best, of couse, is to not be out in -20 to -60 degree weather.... Such a place would be Central Fl - so you are already WIN!