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. |
