(c) The schedule in table 4-1 is based on work equal to that of
marching with a 20-pound pack at the rate of 2.5 miles per hour. Lighter work may be
carried out for longer periods of time.
(d) Lighter work may be carried out for longer periods of time, while
heavier work should be done for shorter time periods. During the midday period,
individuals should rest and keep in the shade as much as possible. Peak wet bulb
globe temperature (WBGT) conditions usually occur between 1200 and 1400 hours.
(e) Local and regional variations may warrant modifications of the work
schedule in table 4-1. Also, acclimatization schedules for unseasoned individuals,
including recruits, should be scaled down to their tolerance.
(4) Water. Provide adequate water for personnel during the acclimatization
period as well as other times.
(5) Acclimatized personnel. Once acclimatized, personnel will retain most
of their adaptation for about one week after leaving the hot environment. If these
individuals are not exposed to work at high temperatures, their acclimatization will then
decrease at a variable rate, the major part of acclimatization being lost within one
(6) Desert/jungle acclimatization. Acclimatization to a hot, dry (desert)
environment increases markedly the ability of men to work in hot, moist (jungle)
environments. However, for proper acclimatization to the jungle environment, living in
the jungle with regulated physical activity is necessary. While carefully and fully
developed acclimatization to a hot, dry environment increases resistance to heat, this
acclimatization does not confer complete protection against the ill effects of heat,
particularly moist heat.
(7) 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. It is a
good idea to have an hour of rest following the noon meal.
d. Physical Condition. How well an individual tolerates heat depends partly on
the person's general physical condition. A person in very good physical condition will
tolerate heat stress much better than an individual whose overall physical condition is
e. Work Schedule. Tailor work schedules 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. These general principles must