4-23. USE OF THE WET BULB GLOBE TEMPERATURE INDEX INDEX
The proponents of the WBGT index have proposed the following as a standard
for application of the index.
a. When the WBGT index exceeds 82, discretion should be used in planning
heavy exercise for unseasoned personnel.
b. When the WBGT index reaches 85, strenuous exercises, such as marching
at standard cadence, should be suspended for unseasoned personnel during their first 2
weeks of training. At this temperature, training activities may be continued on a
reduced scale after the second week of training.
c. Outdoor classes in the sun should be avoided when the WBGT index
d. Strenuous exercise should be curtailed for all recruits and other trainees with
less than 12-weeks training in hot weather when the WBGT index reaches 88.
Seasoned personnel, after having been acclimatized each season can carry on limited
activity at WBGT indexes of 88 to 90 for periods not exceeding 6 hours a day.
As noted in paragraph 4-14, prevention of heat casualties depends largely on the
education of personnel exposed and especially upon supervision by informed
responsible commanders. Every individual exposed to unaccustomed high
temperatures should be informed of the potentially serious results of heat injury, the
general nature of these conditions, and how they can be prevented. Supervisors and
responsible officers must, in addition, be able to identify environmental conditions under
which adverse effects of heat are likely to occur. They should recognize the earliest
signs of heat injury and take appropriate action to prevent the development of cases.
All personnel should be able to apply effective first aid. Mental confusion and
overactivity may precede collapse from heatstroke. Supervisors must be alert to detect
this condition, enforce rest, and obtain medical assistance promptly. Responsible
medical officers should assist commanders in the development of local programs for
heat injury prevention and continuously observe and advise in its applications.