But, what many don't understand is that hypothermia can happen anywhere and any time of year. Technically, hypothermia is a loss of body core temperature. The core is 98.6 degrees F., and that warmth is trying to escape by any means available. Here are the ways your body loses heat:
- Conduction — direct contact with an object that is cooler than the core temp.
- Convection — movement of air around your body carries away the warmth.
- Radiation — your body radiates warmth away from itself.
- Evaporation — damp clothing acts like a "swamp cooler" type of air conditioner for your body.
- Exhalation — with each breath, you lose heat from inside and replace it with cold air.
- Elimination — yup, even the bodily act of elimination transfers warmth from inside.
Of course, if you're in a hot environment and expose yourself to excessive heat and exercise, you can go the other way and end up with heat exhaustion or heat stroke (another issue for another post). But even in the desert or the tropics, when the sun goes down so does the ambient temperature, leaving you vulnerable to hypothermia.
So, what can you do to counteract the body's natural tendency toward temperature loss?
- Get dry. Stop whatever is making you wet. If you're in the water, get out. If you're in wet clothing, get out of them and dry your skin, then get into something (a shelter, dry clothing, etc.) to protect yourself from the breeze. When you're wet, your body will be working overtime on the deadly trio of convection, radiation and evaporation.
- Take shelter from the wind. Dry your hair, because you lose a lot of body heat through the scalp. Cover your head.
- Get a fire started to completely dry your body, hair and clothing.
- Heat water for a warm drink. Add calories to the hot water — chocolate, a soup mix, etc.
- Heat up some food an have a hot meal.
- Wrap in cloth a stone warmed by the fire, and tuck it into your jacket or sleeping bag.
- Use the fire to signal for help — smoke by day, flames by night. The sooner you get rescued, the better.