CLIMATIC INJURY CONTROL
Section I. ENVIRONMENTAL COLD INJURIES
a. Cold injury is defined as tissue trauma produced by exposure to cold. The
type of injury produced depends upon the degree of cold to which the body (or its parts)
is exposed, the duration of exposure, and certain environmental factors. For practical
purposes, cold injuries may be divided simply into "freezing" and "non-freezing" types.
The former is the well-known frostbite (superficial of deep). The non-freezing types are
chilblains, trench foot, and immersion foot. There exists no real justification for
distinguishing between trench foot and immersion foot with respect to management, nor
even to the environmental conditions that are causative. Both result from prolonged
exposure of the feet to wet cold: trench foot to cold, wet socks and boots, immersion
foot to cold water--with or without socks and boots. For present purposes, the term
"trench foot" will be employed to cover both, "immersion foot," and the more
cumbersome, "non-freezing cold injury." Chilblains is the only injury that is not of
significant military importance.
b. Nonfreezing cold injuries may be defined as follows:
(1) Chilblains are swelling and reddening of the skin that usually result from
intermittent exposure to temperatures above freezing, accompanied by high humidity.
(2) Trench foot and immersion foot result from a prolonged exposure to wet,
cold foot gear or outright immersion of the feet at temperatures usually below 50F. At
the upper range of temperatures, exposure of 12 hours or more will cause injury.
Shorter durations at or near 32F will cause the same injury. It is usually associated
with immobilization and dependency of the feet.
c. Frostbite results from exposure to temperatures below the freezing point. The
depth and severity of the injury is a function of the temperature and the duration of
exposure--the lower the temperature, the shorter the time required to produce injury. At
very low temperatures, in the presence of wind, freezing of exposed skin can occur
within a few seconds.
d. Cold injury occurs among the civilian population, but its primary impact is on
the military forces. Cold injury has been recorded as a problem of military importance
since the days of Xenophon, and Alexander of Macedonia. Larrey classically described
the role which cold injury played in the defeat of Napoleon's Army in Poland in 1812.