Injury prevention Workplace exposures

Working in the cold

Stay safe when temperatures drop

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Photo: Missouri Department of Transportation/flickr

What to know

OSHA doesn’t have a standard that covers work in cold environments, but it can enforce its General Duty Clause, which requires employers to provide a workplace “free from recognized hazards.”

OSHA and NIOSH say employers should educate workers about conditions that can cause cold stress, as well as the symptoms of related ailments, including frostbite and trench foot and how to prevent them.

OSHA also advises instructing employees on how to dress appropriately for cold conditions, in addition to monitoring them and providing a place to warm up with hot beverages. Whenever possible, schedule work for the warmest part of the day and use a buddy system to help workers monitor each other.

Another option: the use of radiant heaters or other engineering controls to protect against cold stress. First aid kits should include a thermometer and chemical hot packs.

Workers should have extra gloves, hats, socks, jackets and blankets accessible, and a thermos or container with something hot to drink. They also should avoid touching any metal with bare skin.

What to wear

Many of the recommendations to help prevent cold stress involve clothing and personal protective equipment. Experts say layering clothing provides better insulation. NIOSH health scientist Brenda Jacklitsch said this allows workers to remove layers if they become too warm or if their clothing gets wet.

A waterproof outer layer is important when working in a wet, cool environment, OSHA says, and this layer should provide ventilation to prevent overheating. For middle layers, the agency suggests wool or synthetic material “to provide insulation even when wet,” while an inner layer of wool, silk or a synthetic material such as polypropylene is ideal to keep moisture – including sweat – away from the body.

Body heat tends to escape from the head and other extremities, such as the ears, feet and hands, so it’s important to keep them covered, Jacklitsch says.

Make sure clothing isn’t too tight, because tight-fitting clothing can impede circulation and the body’s source of heat. Boots and footwear should be insulated and waterproof.

CCOHS advises finding the right thickness for socks: If socks are too thick, they can lose their insulating properties if compressed inside footwear and will make that footwear tight, possibly slowing blood flow to the feet and toes.

Conversely, if socks are too thin, workers are at risk of developing blisters.

From the "First Aid" course offered by the National Safety Council. Learn more about NSC first aid and CPR training – including online and classroom training for learners, and courses and materials for instructors

What to watch

Hypothermia is one of the greatest dangers facing people who work in the cold. This medical emergency occurs when the body temperature drops below 95° F.

According to OSHA, an important milder symptom of hypothermia is uncontrollable shivering, which indicates the body is losing heat and trying to rewarm itself.

Other symptoms include fatigue, confusion, loss of coordination and slurred speech. People in the late stages of hypothermia may stop shivering or lose consciousness, or have blue skin, dilated pupils, a slowed pulse and slower breathing.

In cases of hypothermia, call 911 immediately. Move the victim into a warm, dry area and remove wet clothing and replace it with dry garments. OSHA suggests wrapping the victim’s entire body – including the head and neck – in layers of blankets with an additional “vapor barrier” such as tarp or garbage bag. Don’t cover the victim’s face.

NIOSH says to first concentrate on warming the center of the victim’s body – the chest, neck, head and groin.

If assistance is more than 30 minutes away, OSHA recommends giving the victim warm sweetened drinks (but no alcohol) if he or she is conscious. You also can place warm bottles or hot packs on the sides of the chest, groin and armpits. Be prepared to give CPR if the victim isn’t breathing or has no pulse.

Other major types of cold stress:

Frostbite. This condition is the result of freezing skin and surrounding tissue. In severe cases, it can lead to amputation of body parts or severe damage to the body. Signs include white/gray patches on the fingers, toes, noses and earlobes. Skin also may look bluish, gray, pale or waxy.

Workers affected may complain of tingling, loss of feeling or aching, or have blisters. Anyone experiencing frostbite needs to be taken to a warm place as quickly as possible and medical personnel should be alerted. If the feet or toes are affected, don’t let the victim walk because it could cause more damage, NIOSH says.

More first aid tips for frostbite:

  • Once indoors, remove any clothing or accessories that might hinder circulation.
  • Immerse the affected area in warm – not hot – water (temperature should be comfortable to the touch, especially for unaffected areas of the body).
  • Use a loose, dry cloth to protect the frostbitten area until medical help arrives.
  • Don’t rub the affected area – this could damage the skin.
  • Don’t warm the frostbitten area with direct heat from items such as a lamp – this can cause burns.
  • Don’t thaw the affected area if it has the potential to freeze again, because this can cause additional damage.

As with hypothermia, you can give someone experiencing frostbite warm, sweet nonalcoholic drinks.

Trench foot. Also known as immersion foot, trench foot can occur in temperatures as high as 60° F if a worker’s feet are “constantly” wet, NIOSH says. Warning signs include reddening skin, tingling, numbness, leg cramps and blistering. Among the steps to take if a worker is suffering from this condition: Remove shoes and wet socks; dry the feet; and instruct the person to avoid walking, which can further damage tissue.

Chilblains. Chilblains are the painful inflammation of small blood vessels in the skin that occur in response to repeated exposure to cold – not freezing – air, according to the Mayo Clinic. NIOSH adds that the condition can occur in temperatures as high as 60° F. Symptoms may include redness, itching and blisters. Victims should avoid scratching the skin, which should be slowly warmed.

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