(3) Fatality. Immersion of the torso and extremities in water below 50 F, as
in northern latitudes, may result in death in less than one hour due to excessive
lowering of body temperature (hypothermia).
f. Previous Cold Injury. A previous episode of cold injury definitely increases
the individual's risk of subsequent cold injury and not necessarily involving the part
previously injured. However, minor degrees of superficial cold injury, when completely
healed, probably do not predispose to subsequent injury sufficiently to require profiling
or other restriction on assignments.
g. Fatigue. Fatigue contributes to cold injury. Mental weariness may cause
apathy leading to neglect of acts vital to survival. This occurs more frequently in
personnel who have been in combat for 30 days or more without rest.
Frequent rotation of troops from active combat duty for even short periods
lessens the influence of the fatigue factor.
h. Activity. Too great or too little activity may contribute to cold injury.
Over activity can cause the loss of large amounts of body heat by
perspiration. The perspiration can become trapped in excess clothing and markedly
reduce the insulating quality of the clothing.
Conversely, immobility causes decreased heat production by the body
with the danger of resultant cooling, especially in the extremities of the body (fingers,
toes, etc.). In general, though, a decrease in physical activity decreases the exposure
time needed for cold injuries to occur.
i. Nutrition. Lack of food intake or poor nutrition predisposes to cold injury.
The normal military ration of 3600 to 4600 calories provides adequate nutrition.
j. Use of Alcohol. Alcohol affects the blood circulatory system and causes an
increase in loss of body heat. The dangers of excessive lowering of body temperature
(hypothermia) and frostbite are increased greatly under its influence. Alcohol can also
result in carelessness and failure to take adequate protective measures. The use of
alcoholic beverages should be avoided when working in cold environments.
k. Medication. Physicians should advise patients of any adverse effects on
peripheral circulation or sweating when prescribing drugs and medications in cold
l. Concomitant Injury. Experience has shown that injuries resulting in
significant blood loss or shock reduce effective blood flow to extremities and predispose
to cold injury.