(Adapted from the U.S. Army Survival Manual)
Hypothermia is the lowering of the body temperature at a rate
faster than the body can produce heat. Causes of hypothermia
may be general exposure or the sudden wetting of the body by
falling into a lake or river.
The initial symptom is shivering. This shivering may progress
to the point that it is uncontrollable and interferes with an
individuals ability to care for himself. This begins when
the bodys core (rectal) temperature falls to about 35.5
degrees C (96 degrees F). When the core temperature reaches 35
to 32 degrees C (95 to 90 degrees F), sluggish thinking, irrational
reasoning, and a false feeling of warmth may occur. Core temperatures
of 32 to 30 degrees C (90 to 86 degrees F) and below result in
muscle rigidity, unconsciousness, and barely detectable signs
of life. If the victims core temperature falls below 25
degrees C (77 degrees F), death is almost certain.
To treat hypothermia, rewarm the entire body. If there are
means available, rewarm the person by first immersing the trunk
area only in warm water of 37.7 to 43.3 degrees C (100 to 110
Rewarming the total body in a warm water bath should be done
only in a hospital environment because of the increased risk
of cardiac arrest and rewarming shock.
One of the quickest ways to get heat to the inner core is
to give warm water enemas. Such an action, however, may not be
possible in a survival situation. Another method is to wrap the
victim in a warmed sleeping bag with another person who is already
warm; both should be naked.
The individual placed in the sleeping bag with victim could
also become a hypothermia victim if left in the bag too long.
If the person is conscious, give him hot, sweetened fluids.
One of the best sources of calories is honey or dextrose; if
unavailable, use sugar, cocoa, or a similar soluble sweetener.
Do not force an unconscious person to drink.
There are two dangers in treating hypothermia - rewarming
too rapidly and "after drop." Rewarming too rapidly
can cause the victim to have circulatory problems, resulting
in heart failure. After drop is the sharp body core temperature
drop that occurs when taking the victim from the warm water.
Its probable muse is the return of previously stagnant limb blood
to the core (inner torso) area as recirculation occurs. Concentrating
on warming the core area and stimulating peripheral circulation
will lessen the effects of after drop. Immersing the torso in
a warm bath, if possible, is the best treatment for hypothermia.
Steve's Notes: There are actually two types of hypothermia:
slow-onset and sudden-onset. Slow onset is when the body cools
over time, usually in an environment of cold air. The body is
chilled through, and exercise can help. Sudden-onset hypothermia
is usually occurs when the body is immersed in cold water. The
outer extremities of the body can be extremely cold, while the
core isn't. In this case, moving fast or exercising once rescued
can cause blood to start pumping to the extremities, and then
bringing the cold into the core, causing heart failure. Hot liquids,
slow warming from the outside, and staying still is best.
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