b. Movement of Air Over the Body. Any movement of air past the body has
the same cooling effect as wind. Air movement may be produced by walking, running,
skiing, or riding in an open vehicle. The speed of movement must be considered in
addition to natural wind when using the wind chill chart.
c. Clothing as a Protection, It is emphasized that this chart is of value in
predicting frostbite only to exposed flesh. Any clothing or material, which stops or
reduces the wind, will give a degree of protection to the covered area. No attempt
should be made, however, to estimate this protection when using the wind chill chart.
Wet clothing or boots have a much-reduced insulating value and will result in heat loss
nearly equal to that of exposed flesh.
d. Using the Wind Chill Chart. To use the chart, find the wind speed in the
left-hand column and the actual temperature in degrees Fahrenheit in the top row. The
equivalent temperature is found where these two intersect. The description below the
columns indicates the comparative danger of frostbite to exposed flesh under these
conditions. For example, an actual temperature of 23 F with a 20-mph wind is
equivalent in cooling power to a temperature of -6 F (6 degrees below zero) with no
wind. Interpolate for figures between those shown.
e. What the Wind Chill Chart Shows. The wind chill chart shows the cooling
power of wind on exposed flesh, giving the equivalent rate of cooling as compared to
what would be experienced under calm conditions at the lower temperature. No matter
how great the wind velocity, however, exposed flesh will not freeze so long as the
ambient temperature remains above freezing. Other cold injuries, though, can occur at
temperatures much higher than those shown on the chart.
PREVENTION OF COLD INJURIES
Cold injuries are preventable. Successful prevention requires vigorous command
leadership and proper use of preventive measures, which are inspected and enforced.
Of major importance are:
Cold weather training.
The provision of proper clothing and equipment.
Specific preventive measures should be directed toward:
-- Conservation of total body heat.
-- Avoiding unnecessary prolonged exposure of personnel to cold, moisture,
and activities favoring cold injury.