b. Decrease Heat Stress. Heat stress is decreased by:
Reducing the workload
Protecting the individual from the hot environment
These measures are discussed briefly in the following paragraphs.
The human body is highly dependent on water to cool itself in a hot environment. An
individual subjected to high heat stress may lose water in excess of one quart per hour
by sweating. Water losses must be replaced or else rapid decrease in the ability to
work, rise in body temperature and heart rate, deterioration of morale, and heat injuries
will occur. Water loss should be replaced preferably by periodic intake of small
amounts of water throughout the work period.
a. Moderate Activity - Moderate Water Requirements. During a period of
moderate activity with moderate conditions prevailing, water requirements will be one
pint or more per hour per soldier. This is best taken at 20- to 30-minute intervals.
b. Activities/Conditions Increase-Water Requirements Increase. As
activities or conditions become more severe, the water-intake need increases
A person working in a hot environment should drink at least one full
canteen (one quart) every hour.
A person who is performing strenuous physical labor or who is working in
a very hot environment should drink one quart of water every half-hour.
The water should be drunk in small amounts throughout the work period
rather than drinking a large amount of water at one time.
c. Water in Short Supply. When water is in short supply, significant water
economy may be achieved by limiting physical activity to the early morning, evening,
and night hours when the heat load is less and sweating is reduced.
The belief that soldiers can be taught to adjust to decreased water intake is
d. Thirsty or not Thirsty. DO NOT rely on thirst to remind you when to drink
water. People in a hot climate seldom feel thirsty enough to replace all of the water that
is lost through perspiration, urination, and respiration. It is better to drink too much
water than not to drink enough water.