Health Hazards » Cold Stresses

The body can tolerate very little exposure to cold without protective clothing. When exposed to cold temperatures, the body begins to lose heat faster than it is produced. The body cannot adjust itself as well to cold as to heat. Blood vessels will shrink in order to prevent heat loss. Workers in certain outdoor environments are especially susceptible to cold stress.


This occurs when the internal body temperature drops to or below 95° F. Normal muscular and brain functions are impaired. Hypothermia usually happens at very cold temperatures, but can also occur in cooler temperatures, if an individual is submersed in water or becomes chilled from rain.


  • Shivering (uncontrolled)
  • Fumbling hands/ clumsy movements
  • Slurred speech
  • Memory loss
  • Erratic behavior
  • Cool bluish/ purple colored skin


This is the actual freezing of tissue. Exposed skin is susceptible to frostbite when the air temperature is below 0° F or when there are high winds combined with cold temperatures. Frostbite can lead to tissue damage, scarring, and possible amputation.


  • Pale, waxy-white skin color, cool to touch
  • Tingling, stinging, or aching feeling in exposed area, followed by numbness
  • Ears, fingers, toes, and cheeks are areas primarily affected
  • Freezing of muscles and tendons, causing areas to become numb, painless and hard to the touch

Trench Foot:

This condition results from prolonged exposure of the lower extremities to cold 32° F to 50° F and moisture. There is no formation of ice crystals in the tissues. It usually develops slowly, over a period of hours to days.


  • Initially reddened skin, which later becomes pale and swollen
  • Numbness, followed by leg cramps
  • Blister formation, followed by ulceration
  • Instruct workers regarding the selection of proper clothing for cold, wet, windy conditions. Wear at least three layers of clothing:
    -an outer layer to break the wind (gortex or nylon)
    -a middle layer of down or wool to absorb sweat and retain insulation
    -an inner layer of synthetic weave to allow ventilation
    40 percent of body heat can be lost through the head. Wear insulated hats, gloves and footwear.

  • Do the majority of the work in the warmest part of the day.

  • Allow employees to take frequent breaks in shielded areas.

  • Encourage employees to drink warm, non-caffeinated beverages.

  • Work in pairs.

  • Educate the supervisors and employees of symptoms of cold related disorders.

  • Use thermal insulation on equipment handles when temperatures fall below 30° F.

  • Avoid worker fatigue and exhaustion.