Hypothermia by Mike Dugger This information has been compiled from several sources, and the summary below represents a non-professional's interpretation of what he has learned. In particular, I made use of a document compiled and presented by Reed Burnett, one of our former members who is a physician's assistant, during a winter bivy on Mount Taylor. The Search and Rescue Society of British Columbia has one of the best compilations on the subject I have ever seen at http://www.sarbc.org/hypo.html. Hey, I'm no doctor. As always, the reader should consult a professional for an expert opinion. Introduction We require a body core temperature of 96 to 101 degrees F to sustain life. Maintaining body temperature in this narrow range is a balance between heat production and heat loss. Our ability to survive in cold temperatures is due to behavior, not biology. We've used everything from animal skins to wool to fancy, high-tech waterproof and breathable fabrics to keep warm. The body's thermostat is sensitive to less than 1 degree F change in core temperature, and the body responds to this cooling in a variety of ways, depending upon the temperature and rate of cooling. Hypothermia is defined as a body core temperature less than 95 degrees F. Hypothermia can most definitely be fatal if untreated. Heat Production We generate heat by burning fuel. For our bodies, this means metabolizing food. In order to generate this heat by metabolism, we need food for fuel, air for oxygen, and water for the chemical processes of digestion. Here are some interesting numbers on the effect of activity the body's rate of energy consumption. Just sitting around, we burn an average of 100 calories per hour. While shivering, we may burn 500 cal/hour, and hiking uphill with a 40 pound pack burns about 1000 cal/hour! All these calories can come from metabolizing food, or burning stored energy in the form of fat. | |
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