Cold Stress Prevention

Overview

Cold-related illnesses can slowly overcome a person who has been chilled by low temperatures, brisk winds, and wet clothing. Prolonged exposure to freezing or cold temperatures may cause serious health problems such as frostbite and hypothermia. In extreme cases, including cold water immersion, exposure can lead to death.

Frostbite

Frostbite usually affects the fingers, hands, toes, feet, ears, and nose. It is a freezing of the deep layers of skin and tissue. The skin becomes hard and numb and turns a pale, waxy-white in color.

Hypothermia

Hypothermia means "low heat" and is a potentially serious health condition. This occurs when body heat is lost from being in a cold environment faster than it can be replaced. When the body temperature drops below the normal 98.6° F to around 95° F, the onset of symptoms normally begins. The person begins to shiver and stomp feet in order to generate heat. As the body temperature continues to fall, slurred speech, lack of coordination and memory loss develop and the person will stop shivering. Once the body temperature falls to around 85° F, the person may become unconscious, and at 78°, the person could die. Hypothermia can be classified as one of three severities:

• Mild hypothermia
  • Shivering
  • Lack of coordination, stumbling, fumbling hands
  • Slurred speech
  • Memory loss
  • Pale, cold skin
• Moderate hypothermia
  • Shivering stops
  • Unable to walk or stand
  • Confused and irrational
• Severe hypothermia
  • Severe muscle stiffness
  • Very sleepy or unconscious
  • Ice cold skin
  • Death

Wind Chill

Temperature is not the only indicator of an environment in which a cold stress injury or illness could occur. Three factors contribute to cold stress: cold temperatures, wind velocity, and dampness. The following table illustrates frostbite times (bare skin) when exposed to certain temperatures and wind velocities.

Prevention

Clothing Selection

Wearing the right clothing is the most important way to avoid cold stress. The type of fabric also makes a difference. Take the following guidelines into account when preparing for exposure to cold environments:

• Wear several layers of clothing rather than one thick layer. Air captured between layers acts as an insulator.
• Wear synthetic fabrics such as polypropylene next to the skin because these whisk away sweat. Clothing should not restrict flexibility.
• If conditions are wet as well as cold, ensure that the outer clothing worn is waterproof or at least water-repellent. Wind-resistant fabrics may also be required under some conditions.
• Immediately change clothing that becomes wet.
• Use of hats and hoods to prevent heat loss from the head and to protect ears. Balaclavas or other face covers may also be necessary under certain conditions.
• Tight-fitting footwear restricts blood flow. Footwear should be large enough to allow wearing either one thick or two thin pairs of socks. Wearing too many socks can tighten fit and harm rather than help.
• If you become hot while working, open your jacket, but keep hats and gloves on.

Engineering Controls

• Whenever possible, shelter the work area to avoid wind gusts. Use radiant heaters, etc. to warm the work area. Ensure that fuel burning heaters are well ventilated per manufactures recommendations.

Work/Rest

• Avoid prolonged exposures to cold environments. Take frequent breaks in warm, sheltered environments.

Diet/Medications

• Prior to performing work in cold environments eat warm, high calorie foods.
• Avoid caffeine and alcohol.
• Some medications may increase the risk of cold-induced injuries as they inhibit the body’s generation of heat. Certain medications may prevent the body from generating heat normally. These include anti-depressants, sedatives, tranquilizers and some heart medications.
• Some conditions such as diabetes and hypertension will increase the risk of a cold-induced injury or illness.

First Aid

Frostbite

• Seek medical attention immediately
• Move to warm, dry place
• Do NOT rub area in which frostbite developed
• Wrap affected area in a soft cloth

Hypothermia

• Seek medical attention immediately
• Move to warm, dry place
• Remove wet clothing
• Cover victims entire body with blankets
• Administer warm, sugary liquids if alert