Reaction to Cold

Reaction to Cold: How the body responds

Vasoconstriction.

Tachycardia.

Tachypnea.

Brochospasm.

Dehydration. 

They are the major effects of cold that are the root of all other problems. These five body changes are the building blocks of system failure caused by cold environmental conditions. They all stress the healthy body.

Cold conditions do not have to be extreme to cause problems. Even mild decreases in temperature are enough to trigger those five major effects of cold can cause increased heat losses through radiation and conduction. Heat losses can increase 25 to 30 times when a body is in contact with a cold or wet surface.

Any condition or disease that involves vasoconstriction, respiratory or neurological impairment places a person at increased risk during exposure to cold. In general, increased cold exposure risk increases with:

• age < 1
• Circulatory, vascular or neurological disease
• Raynaud's Phenomenon
• Alcohol, tobacco, caffeine, or energy drink use
• Trauma or Hypoglycemia
• Prior cold injury

Better health means better performance in cold environments. Exposure to cold decreases mental capacity with increased risk of injury, accidents and errors

While often considered during the hot summer month, dehydration is a major threat during cold periods. Evaporation, sometimes referred to as insensible losses, increases with cold atmospheric conditions. Respiration moisture losses account results in large amount of fluid loss through evaporation. These respiratory/evaporation losses  increases dramatically in cold environments as the moisture in exhaled breath increases. Dehydration is more prevalent with excessive use of caffeine or alcohol. Prolonged exposure to cold and dehydration are important variables to evaluate as both increase risk for hypothermia.

Environmental exposure to cold is also linked to decreased mental capacity. Reduced mental endurance has been shown to increase the risk of errors and accidents. Responders should be taking this into account when operating in cold environmental conditions for any period of time.  Further, the physical discomfort associated with exposure to cold, even for brief periods, may contribute to decreased mental alertness.

Additionally, there is an increased risk of physical injury while operating in a cold environment. Joints and muscles become stiff and strength decreases. These factors lead to sprains and strains and muscular micro-trauma as well as acute injury. These effects can be seen in the well-conditioned person just as easily as in those who are not in good physical condition.

Factors in remaining warm include maintaining good food/nutrition status, adequate fluid and hydration and maintaining reasonable physical fitness.