e. Definition of a freezing cold injury. Frostbite results from crystallization of
tissue water in the skin and adjacent tissues and is produced by 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 low temperatures in the presence of wind,
freezing of exposed skin can occur within a few seconds.
Cold injury, as it involves a military population, behaves in general according to
accepted epidemiologic principles. A specific agent is present and a variety of
environmental and host factors influence the incidence, prevalence, type, and severity
of the injury. These factors combine in the total causation of cold injury, and the
influence of each may vary in every situation. Careful evaluation of these factors and
their relative effects serves to guide prevention and control activities and dictates
specific measures which must be employed according to condition in the unit
a. Agent Factor. Cold is the specific agent in cold injury and is the immediate
cause of tissue damage. However, if cold is causing loss of body heat which is, in turn,
evaporation must be considered. In other words, the effect of cold cannot be evaluated
only by the temperature of the air.
Radiation--Transfer of heat from the body to an object without physical
(2) Conduction--Transfer of heat from the body to an object in physical
contact such as clothing.
(3) Convection--Cool air making contact with the body and carrying away