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Cold Stress

Learning Objectives

  • Identify cold stress hazards that can exist on the job.
  • Identify the nature, symptoms, and treatment of cold stress.
  • Recognize the precautions for protecting against cold stress.

Available in English, Spanish

25 minutes

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Hypothermia kills around 700 people in the U.S. annually, making it statistically more deadly than floods or tornadoes.

Labor Statistics, OSHA


If you are exposed to extreme cold in your work environment, you can be at risk of what the Occupation Safety & Health Administration (OSHA) calls “cold stress” illnesses and injuries. Ocean fishermen, energy exploration workers in the North and South, high-altitude workers, and construction personnel out during the winter months are those most commonly at risk. Those most affected by cold stress are people working in outdoor conditions, but those working indoors, where there is insufficient building insulation, ventilation, heating, are also at risk. Those at most risk are workers without shelter or outdoors and that are not adequately protected against cold conditions or trained to recognize the symptoms and treatment of cold stresses.

Preparedness and awareness is so essential to surviving exposure to cold stress. Knowing how the body regulates temperature and understanding warning signs is important because the weather outside does not have to be freezing or below for a person to suffer the effects of prolonged exposure to low temperatures. An understanding of the conditions, signs and symptoms of cold stresses is critical to safety. Underestimating the importance of this knowledge can lead to serious injuries.  

The conditions that combine to create cold stress can vary across different areas of the country. In regions relatively unaccustomed to winter weather, near freezing temperatures are considered factors for "cold stress." Whenever temperatures drop decidedly below normal, and as wind speed increases, heat can more rapidly leave your body. These weather-related conditions may lead to serious health problems.  

Extreme cold weather is a dangerous situation that can bring on health emergencies because when exposed to cold temperatures, your body begins to lose heat faster than it can be produced. Prolonged exposure to cold will eventually use up your body's stored energy.

The result is hypothermia, or abnormally low body temperature. A body temperature that is too low affects the brain, making the victim unable to think clearly or move well. This makes hypothermia particularly dangerous because a person may not know it is happening and will not be able to do anything about it.

Cold water immersion creates a specific condition known as immersion hypothermia.

It develops much more quickly than standard hypothermia because water conducts heat away from the body 25 times faster than air. Typically, people in temperate climates don’t consider themselves at risk from hypothermia in the water, but hypothermia can occur in any water temperature below 70°F.

Frostbite is an injury to the body that is caused by freezing. Frostbite causes a loss of feeling and color in the affected areas. It most often affects the nose, ears, cheeks, chin, fingers, or toes. Frostbite can permanently damage body tissues, and severe cases can lead to amputation. In extremely cold temperatures, the risk of frostbite increases in workers with reduced blood circulation and who are not dressed properly.  

Trench foot is also known as immersion foot. Like immersion hypothermia, this injury results when the feet have prolonged exposure to wet and cold conditions. Trench foot can occur at temperatures as high as 60 degrees F, if the feet are constantly wet. Wet feet lose heat 25-times faster than dry feet.

Chilblains are caused by the repeated exposure of skin to temperatures just above freezing to as high as 60 degrees F. The cold exposure causes damage to groups of small blood vessels in the skin. This damage can be permanent and the redness and itching may return with additional exposure.

What are the easy to recognize symptoms? Well, we’ve all experienced shivering the most common symptom of cold stress. But after shivering comes fatigue, loss of coordination, and confusion. Eventually, according to the Centers for Disease Control and Prevention (CDC), the skin will pale to blue, pupils will dilate, breathing will slow down, and shivering will stop. Then, consciousness is lost.

What about prevention? It’s good to start by strictly scheduling and monitoring personnel exposure to the elements, but on the preparedness front, dressing for the weather is the most important consideration. Wearing several layers of loose, warm clothing, for insulation, is the best practice. Knowing what to avoid is also key; shelter from wind, which chills the body and cuts through insulating layers, is smart. Of course, staying dry is also critical.

Course Outline
  • Introduction
  • Types of Cold Stress
  • Preventions/Protections of Cold Stress
Regulations