The better the person's physical condition however, the quicker acclimatization is
a. The Process of Acclimatization. Acclimatization to heat begins with the first
exposure and is fairly well developed by the end of the second week.
Individuals who are unusually susceptible to heat will require additional
time for acclimatization.
Full acclimatization (the ability to perform a maximum amount of
strenuous work in the heat) is attained most quickly by graded, progressively increasing
work in the heat.
Resting for 3 or 4 days in the heat with activity limited to that required for
existence results in definite, but only partial, acclimatization.
Physical work must be accomplished, but should be limited to brief
A day or two of intervening cool weather will not interfere significantly with
b. Work-Rest Schedule. A schedule should be established which provides for
alternating work and rest periods. Although advantage should be taken of the cooler
hours in accomplishing a portion of the work, the schedule should include gradually
increasing exposure during the hotter parts of the day rather than complete exclusion of
work at that time.
The work period should be divided so that a person works and rests in
When necessary for the accomplishment of a given task, two details can
be arranged to alternate work.
c. Water. Adequate water must be provided at all times.
d. Meals. Under conditions of heat stress, meals should be cool rather than hot.
The heaviest meal should be served in the evening rather than at noon. An hour of rest
following the noon meal is beneficial.
e. Desert and Jungle Acclimatization. Acclimatization to a hot, dry (desert)
environment increases markedly the ability of men to work in a hot, moist (jungle)
environment. Regulated physical activity is required, however, for proper