5 WAYS TO... Y our body loses heat in 5 ways, so protection must address. these 5.

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1 5 WAYS TO... Y our body loses heat in 5 ways, so protection must address these 5. Radiation: heat loss from exposed skin. Heat radiates out as the capillaries bring warm blood to the surface of the skin. An energy exchange is happening. You use energy to maintain warm skin. 1

2 Evaporation: This occurs when the body produces sweat, and it evaporates from the skin, dropping the skin temp. Again, the body will try to keep up with this energy exchange if it can. Convection: This refers to the addition of air moving across the wet exposed skin that accelerates the cooling process. Wind chill is another term for this. This energy exchange is hard for the body to keep up with. Respiration: As air passes through the nasal cavities it is warmed and humidified, so that air that reaches the lungs is warmed and moist. The Nasal airways are lined with cilia and kept moist by mucus secretions. The combination of cilia and mucous helps to filter out solid particles from the air and warm and moisten the air, which prevents damage to the delicate tissues that form the Respiratory System. Again, an energy exchange. Conduction: This is the energy exchange between two masses of differing temperatures. My butt on a big rock is attempting to warm the rock, and the rock is slowly warming. But the energy loss from my butt will exceed the warming of the rock because of the density and thermal mass of the rock. On the other hand, if I were sitting on a thick foam pad, I would win that energy exchange. The surface of the pad would retain my heat, and my butt would not get cold. A much slower energy exchange. 2

3 Clothing First line of defense is clothing. The enemy in cold weather is moisture. Your first layer must be wicking. Then insulation. Then a waterproof outer layer. Best insulators are fleece and wool. Goose down is a superior insulator, but it loses its insulative qualities when wet. Wool is far more durable than fleece, but it is heavy. Fleece sheds water very well and is light, but will not work for an outer layer as it is susceptible to wear and embers from a fire. Several light layers are better than one heavy layer. So I always start with polypropylene underwear. Then a synthetic shirt like an Underarmor. Then a fleece pullover, then a waterproof shell. If it is below 20 F then I add a heavy wool sweater. If I am exerting, I must not allow myself to sweat. Sometimes when I would snowshoe for a long period of time, I would strip down to the poly undershirt, and with the high level of exertion I would not be cold. All the sweat was wicked away from my body and evaporated. Then when I stopped for a short break, I would add a fleece pullover whenever I felt cold. 3

4 The most important key to dressing to stay warm, is not to wear anything that is made of cotton. Cotton retains moisture, and will cause you to get chilled quickly. By the way, you want to wear cotton in the tropics for precisely that reason; it cools you down. In extreme cold, say below 10 F, or in slightly warmer temps where you are not moving, you need more and better insulation. I have a King of the Mountain coat that I cannot even wear till the temps are below 10 F. It is designed for extreme cold and sitting in a tree-stand for long hours. It has matching bib overalls that cover you all the way to the nipple line. That keeps the core extra warm. Always wear a hat and neck gator. I have a hard time wearing a stocking cap for very long. It makes my scalp hurt after a while. For those who don t know me, I am an incorrigible whiner. So having a hood to replace the hat every so often works for me and minimizes my whining. Your mileage may vary with the hat thing. My friend, Neil Strauss, wears a stocking cap all winter. But his head is shaved. Keeping your head and neck warm are really crucial however. I have studied this with thermal imagers. If your head is uncovered, you lose a lot of heat. I do not know how much, but a lot. Removing the hat is also a good way to regulate temperature. I also wear a neck gator when I am outside in the cold. A scarf does the same thing, but I prefer the gator as it can fill in as a balaclava, a hat, or an ear warmer. 4

5 Feet Good socks and boots can save your feet. When I was a teenager, I managed to get some fairly severe frostbite on my toes. That has always affected my ability to keep my toes warm. There are so many footwear choices that I cannot begin to address them all. I like thinsulate insulated boots for winter. However I am not a fan of waterproof breathable membranes because although they claim to be breathable, my own experience is that they retain way too much sweat inside the boot. And like I said before, moisture is the enemy of warm. I always wear wool socks. All the time. No matter what. In winter, wool socks are the first layer. If I am hiking or cross country skiing or snowshoeing, then I will wear a polypropylene liner sock, which keeps the friction of those activities between the layers and not on my feet. This seriously reduces blisters. Year around Usually medium weight socks will be sufficient. My favorite boots for cold have always been Sorel Caribou with the wool liners. They sold the company a few years back, and now the liners are not felted wool. Call me old fashioned, but prefer the felted wool. I recently bought some Baffin boots that are advertised to be warm to -100 F. Probably overkill. Wear boots appropriate for the temp and activities. Baffin boots are not designed for hiking. Thinsulte hiking boots are better if you are doing a lot of hiking. 5

6 Hands For hands, if you are doing any work in the cold, you need dexterity, which you lose as your hands get cold. My first layer is wool gloves with the first two fingers and the thumb cut short. For colder weather, I prefer mittens. The best low-cost ones I have found are Army surplus wool mittens. They have a patch of fake fur on the back of the hand, and a felted wool liner. They have the string that goes between them that you can run up your sleeve and across your back. Bill Cosby refers to these as idiot mittens, because as he says, you can pull on one mitten and the wearer smacks himself in the face. It doesn t quite work that way, but it keeps you from losing them. I prefer just to put the cord around my neck so they do not get in the way of any work I am doing with them off. I have found chemical hand warmers are convenient. They have some tape-on larger versions to put on your inner thighs or kidneys, which sound intriguing. And some boot inserts as well. They may be good short term, they advertise 6 hours of warmth, but I am not seeing that as a long-term solution. They may be good in a go-bag or car-kit however. But if you follow the layering protocol, they are probably unnecessary. Some basic protocols around working outside: I already mentioned layering, also removing and adding layers to prevent sweating. 6

7 Always wear gloves with mittens over them in extreme cold. I will say anything below 20 F is extreme. My daughter lives in Wyoming and they had a night recently that was -50. That is a whole other level of cold. Food and Liquids Replenish your energy with a combination of simple and complex carbs and fat. When I sleep in the cold, I always keep a bag of Peanut M&Ms next to my bag. If I get cold, the M&Ms have an amazing regenerative effect. You are in effect, stoking the furnace. That is why hikers carry trail mix. Butter: gross but effective. Once, after we d been snowshoeing for several hours, we burned all the glycogen out of our systems, and when we stopped, we were completely shot. And the mountain temps were very cold. An ice climbing friend told me his buddy s solution to being bagged at the end of a day of climbing. He took a cube of butter, rolled it in sugar and ate it. I was kinda grossed out at the thought. But then I tried it at the end of a log exerting day, and presto. Instant regeneration. Extreme I know, but like a shot of adrenaline. Keep hydrated. I mentioned respiration as a means of losing heat. In colder temps, you are drawing in dry cold air and exhaling warm wet hair. There is an energy exchange happening here that does not happen in 7

8 warmer weather. As a result, you lose a lot of moisture in breathing. Rehydrating can be as regenerative as eating M&Ms. I mentioned the five ways the body loses heat. Proper outdoor clothing, food and hydration, should address all of them. Kevin Reeve is the founder of onpoint Tactical, llc, a pioneer in the field of Urban Survival and Urban Escape & Evasion. onpoint Tactical trains professionals and select civilians in Scout skills, Off-grid medicine, and more. Visit us on FACEBOOK, TWITTER and website Copyright Kevin Reeve, onpoint Tactical