With much of the country enduring one of the coldest winters in recent history, it’s a good idea to consider how environmental cold can affect workers exposed to cold temperatures. Exposure to extreme temperatures puts workers at risk of cold stress, especially recreational workers, snow cleanup crews, construction workers, police and firefighters, transit workers, landscaping services, and support activities for oil and gas operations.
Cold stress is the driving down of skin temperature, and eventually internal body temperature, by cold temperature, increased wind speed that causes heat to leave the body more rapidly, and wetness, even from sweat. When the body is unable to warm itself, cold-related illnesses and injuries, permanent tissue damage, and even death may result.
Types of cold stress include trench foot, frostbite, and hypothermia. Trench foot is a non-freezing injury of the feet caused by prolonged exposure to wet and cold. It can occur in temperatures as high as 60 degrees if feet are constantly wet. Feet are especially at risk because wet feet lose heat 25 times faster than dry feet. Symptoms of trench foot include reddening skin, tingling, pain, swelling, leg cramps, numbness, and blisters.
Frostbite is caused by the freezing of the skin and tissues. It can cause permanent damage to the body and, in severe cases, can lead to amputation. Those with poor circulation or who are not dressed properly for extreme cold are most at risk. The symptoms of frostbite include reddened skin on the fingers, toes, nose, or earlobes that develops gray or white patches, tingling, aching, blistering, and loss of feeling.
Finally, hypothermia, or abnormally low body temperature, occurs when the normal body temperature drops to less than 95 degrees. Exposure to extreme cold causes the body to lose heat faster than it can be produced. Prolonged exposure to cold eventually uses up the body’s stored energy and the result is hypothermia. While most likely to occur at very cold temperatures, hypothermia can occur at cool temperatures if one becomes chilled from rain, sweat, or immersion in cold water.
While OSHA does not have specific standards that address working in cold environments, employers have a duty to protect workers from recognized hazards, including cold stress hazards. Employees, thus, should be trained on how to recognize conditions that can lead to cold stress and its symptoms; how to prevent it, including selecting the proper clothing for cold, wet, and windy conditions; and what to do to help those who are affected. Employers should also monitor their workers, schedule frequent, short breaks in warm dry areas, implement the buddy system, provide warm beverages, and, where possible, provide engineering controls such as radiant heaters.
For more information on cold stress, check out this Guide from OSHA.
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