Did you know there is no such thing as a “Warm” coat? I guess that is not quite right. Let’s say a coat or a sleeping bag is not warm, unless you put it into the oven and warm it up, or someone just took it off. It is true, and knowing facts like this helps us stay warm.
The key is to prevent heat loss, unless it is summer; then we may want to increase heat loss. Working with these things allows us to stay reasonably comfortable, “all of the time.”
It may sound minor, but for what it is worth, keeping warm is quite a job. To do it requires attention to several things that “revolve around the five ways that we lose heat.” Just preventing heat loss is only part of the picture. Let’s look at heat loss first.
There are five ways the body’s heat escapes:
1. Convection this is the moving air currents as we walk, ski, when the wind blows etc. Gore-Tex makes a great wind stopper (**Our third layer function) , while helping to prevent moisture build up on the inside of the garment. For more information, Summit Magazine — Gore-Tex and getting the most from it.
2. Conduction is like when you sit down on a cold rock. It conducts heat away from us. Here’s a funny fact: Unless we are sitting around a fire, heat moves away from us. That is one reason we use closed cell foam pads under our sleeping bags. In the winter time you should at least double them up, or use an air mattress that has insulation in it. Look for the “R” rating.
3. Radiation is the third way we “lose” heat. When we walk around without a hat we “radiate” heat away from us, or in the summer, the sun “radiates” heat into our head.
“The head and neck accounts for 50% to 75% of the body’s heat loss. It makes sense if you think about it. They are like a chimney venting heat to the environment around us. It is done via “convection” and “radiation.”
Also the skin around the head has tons of veins that allow for heat transfer. Notice how even a small cut on the face bleeds quite profusely. Even wounds heal more quickly there. The feet are a special case, we must pay good attention to them. Wool for hands and feet, or at least, wool is part of the combination to warm tootsies and fingers.
“If your feet are cold put on a hat.”
The reason putting a hat on can help (there are other things that contribute to making this work.) is because that heat is now available to go to your hands and feet. Your head, brain, neck, heart, lungs, kidneys, liver, etc. are vital and the body knows that, so when it starts to get cold it will shut blood flow down. The skin, feet, legs, arms, and hands can get down to 50° F and still recover. If our core temperature drops down to room temperature about 70° F to 80°F +/- some, our heart will stop beating and life as we know it will change drastically.
Another fact is, “It is easier to stay warm, than to get warm.” A refrigerator does not get cold by adding cold, it becomes cold when we remove the heat. Kind-of like a dark room. It does not get dark by turning on the dark, but rather by turn off the light.
Sounds different, but these understandings go a long ways towards making us happy, warm, and enjoying the winter time. I have spent months on the coldest mountain on earth. That experience has taught me many lessons that make for a comfortable experience while out of door is the winter environment.
4. “Respiration” is the fourth way we lose heat. But it is a little bit impractical to stop breathing, but there are things we can do to minimize it. Wearing a scarf and breathing through it help catch our heat as it goes out, and brings it back in as we inhales.
Small idea but it helps. Here’s another principle to be conscious of. Submarine sleeping is not advisable under most conditions. “I have learned never to say never, and
never generally don’t say Always.” When you sleep with your head in your sleeping bag, the moisture from you body gets your bag wet, violating the five rules for staying warm: 1. Stay Dry 2. Stay Dry 3 . Stay Dry 4 . Stay Dry and 5. . Stay Dry
5. “Evaporation” When moisture evaporates it takes heat with it. That is why swap coolers work. That is one reason we dress in layers. The vapor transmission layer mover the moisture away from our skin.
I plan to do some more articles on staying warm, but for now I would like to recommend you pick up a copy of my book called: Winter Fun-damentals. Cold Weather Skills and Equipment.
** For more on this layer function, “See my article “There is Nothing Wrong with Gore-Tex” (published in Summit Magazine or Off Belay) a copy of it may be in my published articles section? I will check and try to include it there)