Heat

by Seth Recarde

Why are shelter and fire among our first priorities in survival? What makes them so important? Shelter and fire regulate our temperature. The bodies of all warmblooded creatures will only function properly in a narrow range o f temperatures. When a body gets too hot, it experiences heat stroke, where the brain literally cooks inside the skull. When a body gets too cold, it enters hypothermia, where the body shuts down in an attempt to maintain heat in the body core. These can all be prevented with proper shelter and fire.

There are five ways the body looses heat. An understanding of these principles will help you determine the best clothing, shelter, and fire for any given situation. A good way to remember these is by using the memory aid B-R-A-C-E.
B - Breathing
R- Radiation
A - Air Convection
C - Conduction
E - Evaporation

Breathing: A fair amount of heat is exchanged through breathing. Breathing the vapor from a cup of hot tea can greatly reduce the amount of heat lost compared to breathing cold air. Breath through your nose if you are hiking, stalking, etc. in cold weather. This helps pre-warm the air before it hits your lungs.

Radiation: Your body radiates heat just like a fire or hot rock. You can trap this heat close to your body using clothing and shelter. You can add heat through radiation by sitting in the sun, next to a fire, or adding a few warm rocks to your debris hut. If you are too hot, place a barrier between you and the source of heat.

Air Convection: Air moving across the skin blows away the heat generated by the body. Loose weave clothing or holes in your shelter allow heat to be blown away by breezes or gusts of wind. Wind breaks around shelters and fires will keep heat where you want it. Put a belt on over your coat and wear a bandana or tie off the cuffs of your pants at the ankles to prevent air movement up and through your clothing.

Conduction: When two objects of different temperatures come into contact, the warmer object will transfer heat to the cooler object until they are the same temperature.

You build a thick, well insulated debris hut with a tight door, yet fail to stuff the floor with enough debris. What happens? The 50 degree (F) earth sucks away your body heat. Insulate well the contact points between you and any object that will steal your heat. If you get hot, get as much bare skin as you can in contact with a cooler object.

Evaporation: Moisture on the skin absorbs heat until it vaporizes. It takes a great deal of energy to bring water to this point, causing the body to cool rapidly. In cold weather, do your best to avoid sweating. If you do get soaked, take off your wet clothing and change into something dry as soon as possible. Water absorbs body heat 25 times faster than air, making it a very efficient killer.

Keep these principles in mind when you build shelters, chose clothing, or make fire. Use them to your advantage. A few simple changes can turn a cold, miserable night in the woods in a comfortable and relaxing evening spent enjoying nature. Thanks to Don Paul for the BRACE info. Have fun and enjoy the heat.

From True Tracks, Summer-Fall 1996, published by the Tracker School.
For more articles from True Tracks, visit the Tracker Trail website.