f. Continual Heat Watch. While carefully and fully developed acclimatization
increases resistance, it does not confer complete protection against ill effects of heat.
g. How Long Acclimatization Lasts. Once acclimatized, the soldier will retain
his adaptation for about 2 weeks after leaving the hot environment. If he is not exposed
to high temperatures thereafter, the acclimatization will then decrease with the major
portion usually being lost within one month.
4-18. WORK SCHEDULES
Work schedules must be tailored to fit the climate, the physical condition of personnel,
and the military situation. Close supervision by medical officers, responsible
commanders, and experienced paramedical personnel is essential in achieving
maximum work output with minimum hazard. Certain general principles must be
considered when planning work schedules.
a. The Workload. The amount of heat produced by the body increases directly
with increasing work. Therefore, reduction of workload markedly decreases the total
b. The Workload in the First Days of Acclimatization. Workloads and/or
duration of physical exertion should be less during the first days of exposure to heat and
should be gradually increased to allow acclimatization.
c. Heavy Work. While decisions to modify work schedules must be governed
by the particular local situation, work should be scheduled for the cooler hours of the
day, such as early morning or late evening.
d. Work-Rest Periods. Alternate work and rest periods. Rest periods are
discussed in paragraph 4-19.
e. Night High Temperature. Exposure to high temperature at night as well as
in the daytime will decrease the amount of work that men can perform effectively.
f. Water in Short Supply. Workloads must be reduced at high temperatures
when dehydration resulting from excess sweating and lack of water replacement occurs.
When water is in short supply, working in the early morning and evenings will allow
much more work to be accomplished for the expenditure of a given amount of water
than working during the hottest hours of the day.
g. Direct Sun Work. Work in the direct sun should be avoided as far as
possible on hot days.
h. Standing in Heat. Unnecessary standing at attention in the heat should be
avoided because continued standing places an added burden on the circulation.