190 Training for Specific Environments
" Optimize acclimation by a carefully scripted exercise program from the med-
ical department." Plan for decreased physical performance the first two weeks.
" Maintain proper hydration.
" Be aware of any illness that may predispose to dehydration (diarrhea, vomit-
ing, fever)." Always be aware of the warning signs of heat illness: Pay attention to your
body. Slow down or stop if signs or symptoms of heat injury become appar-
ent." Avoid drugs and other substances that predispose to dehydration or heat inju-
ries.Training in Cold Environments
Cold climates represent the harshest environments and pose the greatest threat to
survive that SEALs face. An unprotected man in an extremely cold environment will perish
much faster than when exposed to extreme heat. In cold weather, the human body attempts
to maintain a warm core temperature primarily by physiologic mechanisms and behavioral
adaptations:" Increased Metabolic Heat Production: This occurs as the body's fuels (car-
bohydrates, fats and proteins) are metabolized or “burned” at the cellular
level. Shivering represents involuntary muscle contractions that can increase
the body’s metabolic rate five to six times above normal." Peripheral Vasoconstriction: Blood vessels near the surface of the skin con-
strict or narrow in an effort to divert warm blood away from the cool surface
of the skin." Behavioral Adaptations: Mans greatest asset in cold weather is his ability to
create a warm micro-environment by wearing appropriate protective clothing
or seeking shelter. He can also increase resting metabolic heat production by
10 times through vigorous exercise.What is a cold environment? As with a hot environment, the temperature alone is
not necessarily the best indication of coldness. In the heat, humidity, and in the cold, the
wind, can greatly change your comfort level. In the cold, wind accelerates heat loss by
replacing the warm layer of air surrounding the body with colder air. As a rule, you can be