Workers exposed to extreme cold or who work in cold environments may be at risk for cold stress and other cold-related illnesses and injuries.

COLD STRESS

Workers who are exposed to extreme cold or work in cold environments may be at risk of cold stress. Extreme cold weather is a dangerous situation that can bring on health emergencies in susceptible people, such as those without shelter, outdoor workers, and those who work in an area that is poorly insulated or without heat. What constitutes cold stress and its effects 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.

Working in the Cold

Depending on where you reside and work this season, Old Man Winter might be knocking on your door, bringing you snow, ice, and chilling temperatures. 

For those in warmer areas of the country, it may be difficult to imagine some winter weather extremes. For instance, according to the NOAA National Climate Extremes Committee, the existing record for lowest temperature in the United States was -80°F (-62.2°C) in Prospect Creek, Alaska, in 1971. Luckily, most workers will not encounter conditions quite so extreme.

Workers exposed to extreme cold or who work in cold environments may be at risk for cold-related illnesses and injuries. Susceptible workers, such as those working without shelter, outdoors, or in an area that is poorly insulated or without heat, may be put into a dangerous situation when cold weather prevails. What constitutes cold stress and its effects can vary across different areas of the country. In regions relatively unaccustomed to winter weather, even near freezing temperatures can put unaccustomed workers at risk.

Whenever temperatures drop decidedly below normal and as wind speed increases, heat can more rapidly leave the body. If workers are unable to keep warm, these cold conditions may lead to serious health problems, such as chilblains, trench foot, frostbite, and hypothermia. Hypothermia in particular, can be deadly. If a worker experiences an abnormally low body temperature, the brain is affected, making it difficult or impossible to think clearly or move well. This makes hypothermia particularly dangerous because a person may not know it is occurring and may be unable to take actions to warm themselves or seek medical care.

There are a few recommendations that employers can follow to protect workers from cold stress:

• Schedule routine maintenance and repair jobs in cold areas for warmer months.
• Schedule cold jobs for the warmer part of the day.
• Reduce the physical demands of workers.
• Use relief workers or assign extra workers for long, demanding jobs.
• Provide warm liquids to workers to consume.
• Provide warm areas for use during break periods.
• Monitor workers who are at risk of cold stress.
• Provide cold stress training that includes information on the following:
  • risk factors
  • prevention
  • symptoms
  • the importance of monitoring yourself and coworkers for symptoms
  • first aid
  • personal protective equipment

In addition, workers should avoid exposure to extremely cold temperatures when possible. When cold temperatures cannot be avoided, workers should follow these recommendations:

• Wear appropriate clothing.
  • Wear several layers of loose clothing. Layering provides better insulation.
  • Tight clothing reduces blood circulation. Warm blood needs to be circulated to the extremities. When choosing clothing, be aware that some clothing may restrict movement, resulting in a hazardous situation.
• Make sure to protect the ears, face, hands, and feet in extremely cold weather.
  • Boots should be waterproof and insulated.
  • Wear a hat; it will keep your whole body warmer. Hats reduce the amount of body heat that escapes from your head.
• Move into warm locations during work breaks; limit the amount of time outside on extremely cold days.
• Carry cold weather gear, such as extra socks, gloves, hats, jacket, blankets, a change of clothes, and a thermos of hot liquid.
• Include a medical and environmental thermometer and chemical hot packs in your first aid kit.
• Avoid touching cold metal surfaces with bare skin.
• Monitor your physical condition and that of your coworkers.

Stay safe and warm this winter! For additional information on cold stress, visit NIOSH Cold Stress.

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Cold Stress - Cold Related Illnesses

Types of Cold-related Illnesses

Hypothermia | Frostbite| Trench Foot| Chilblains

Hypothermia

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.

Symptoms

Symptoms of hypothermia can vary depending on how long you have been exposed to the cold temperatures.

Early Symptoms

• Shivering
• Fatigue
• Loss of coordination
• Confusion and disorientation

Late Symptoms

• No shivering
• Blue skin
• Dilated pupils
• Slowed pulse and breathing
• Loss of consciousness

First Aid

Take the following steps to treat a worker with hypothermia:

• Alert the supervisor and request medical assistance.
• Move the victim into a warm room or shelter.
• Remove their wet clothing.
• Warm the center of their body first-chest, neck, head, and groin-using an electric blanket, if available; or use skin-to-skin contact under loose, dry layers of blankets, clothing, towels, or sheets.
• Warm beverages may help increase the body temperature, but do not give alcoholic beverages. Do not try to give beverages to an unconscious person.
• After their body temperature has increased, keep the victim dry and wrapped in a warm blanket, including the head and neck.
• If victim has no pulse, begin cardiopulmonary resuscitation (CPR).

Frostbite

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 is increased in workers with reduced blood circulation and among workers who are not dressed properly.

Symptoms

Symptoms of frostbite include:

• Reduced blood flow to hands and feet (fingers or toes can freeze)
• Numbness
• Tingling or stinging
• Aching
• Bluish or pail, waxy skin

First Aid

Workers suffering from frostbite should:

• Get into a warm room as soon as possible.
• Unless absolutely necessary, do not walk on frostbitten feet or toes-this increases the damage.
• Immerse the affected area in warm-not hot-water (the temperature should be comfortable to the touch for unaffected parts of the body).
• Warm the affected area using body heat; for example, the heat of an armpit can be used to warm frostbitten fingers.
• Do not rub or massage the frostbitten area; doing so may cause more damage.
• Do not use a heating pad, heat lamp, or the heat of a stove, fireplace, or radiator for warming. Affected areas are numb and can be easily burned.

Trench Foot

Trench foot, also known as immersion foot, is an injury of the feet resulting from 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. Injury occurs because wet feet lose heat 25-times faster than dry feet. Therefore, to prevent heat loss, the body constricts blood vessels to shut down circulation in the feet. Skin tissue begins to die because of lack of oxygen and nutrients and due to the buildup of toxic products.

Symptoms

Symptoms of trench foot include:

• Reddening of the skin
• Numbness
• Leg cramps
• Swelling
• Tingling pain
• Blisters or ulcers
• Bleeding under the skin
• Gangrene (the foot may turn dark purple, blue, or gray)

First Aid

Workers suffering from trench foot should:

• Remove shoes/boots and wet socks.
• Dry their feet.
• Avoid walking on feet, as this may cause tissue damage.

Chilblains

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 the capillary beds (groups of small blood vessels) in the skin. This damage is permanent and the redness and itching will return with additional exposure. The redness and itching typically occurs on cheeks, ears, fingers, and toes.

Symptoms

Symptoms of chilblains include:

• Redness
• Itching
• Possible blistering
• Inflammation
• Possible ulceration in severe cases

First Aid

Workers suffering from chilblains should:

• Avoid scratching
• Slowly warm the skin
• Use corticosteroid creams to relieve itching and swelling
• Keep blisters and ulcers clean and covered