Resources Guidance Seasonal safety: Winter Injury prevention Workplace exposures

Out in the cold

How to avoid injuries and illnesses when temperatures plummet

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As CEO of the Snow and Ice Management Association, Martin Tirado is particularly empathetic toward outdoor workers who have to brave winter weather.

His Mequon, WI-based organization offers a personal protective equipment checklist to its members and instructs them on how long their workers should stay out in cold conditions before taking an all-important break.

“Typically – and it kind of depends on the temperature – but out of one hour of work, 15 minutes should be inside somewhere warming up,” Tirado said.

Limiting worker exposure to cold can go a long way toward preventing cold stress injuries and illnesses such as frostbite, hypothermia, trench foot and chilblains.

The big three

Three major factors to keep in mind when working outdoors are air temperature, wind and moisture.

The American Conference of Governmental Industrial Hygienists developed a sliding scale based on those three variables, which OSHA turned into a cold stress equation informative graphic. The graphic shows that exposed skin is in danger of freezing within one minute when the temperature is between -20° and -30° F and no wind is present.

With winds around 20 mph, that danger zone threshold begins at 10° F because blowing air can take away at least part of the bubble of heat that the body creates.

Trench foot and chilblains (for more on these conditions, see below) can occur at temperatures as high as 60° F, according to NIOSH.

Brenda Jacklitsch, a health scientist in NIOSH’s education and information division, said moisture on the skin and any wind can cause the body to lose heat. That means dressing properly for the cold is critically important for workers.

What to wear

Experts recommend using breathable layers, making sure clothing isn’t so tight that it cuts off circulation or impedes movement. Layering also allows workers to remove clothing if they become too warm from exertion or weather conditions change.

“There needs to be a balance that’s found between what you’re wearing and the type of job you’re doing,” Jacklitsch said. “You need to be aware that having extra PPE on may restrict some of your movements, so you need to be more careful.”

Layering clothing can provide better insulation against the cold because the body can warm the trapped air between the layers, Jacklitsch said. If the fabric is breathable, it will keep perspiration from building up on the skin and pulling away needed body heat.

Experts also suggest workers wear items such as hats and hoods, or liners under their hard hats, to decrease the amount of heat escaping from the head. Jacklitsch said a knit cap that covers the ears or part of the face is likely to keep a worker warmer than a ball cap.

Regarding footwear, experts suggest insulated, waterproof boots with proper traction. The Canadian Center for Occupational Health and Safety goes a bit further, calling for “felt-lined, rubber-bottomed, leather-topped boots with removable felt insoles” because the leather allows the boots to breathe and the air to evaporate any perspiration.

Gloves also should be insulated and water-resistant if necessary, according to OSHA.

What to do

OSHA doesn’t have a defined standard on working in the cold but states that employers must protect workers from hazards in accordance with the Occupational Safety and Health Act.

OSHA and NIOSH recommend that employers:

  • Schedule work to be completed during the warmest part of the day.
  • Tell workers to pair up (buddy system) so they can monitor co-workers.
  • Provide extra workers for longer, more demanding jobs.
  • Set up a warm, dry shelter for workers to use during breaks.
  • Provide warm liquids to drink, avoiding caffeine and alcohol.
  • Use engineering controls such as radiant heaters, if possible.
  • Ensure you have a method to communicate with all workers, especially those in remote locations.

Additionally, NIOSH advises workers to avoid touching metal surfaces with their skin, and to bring extra clothing. Other items workers should have with them include blankets, a thermos with a hot beverage, and a first aid kit with chemical hot packs and a thermometer.

OSHA warns workers to avoid working fatigued or exhausted “because energy is needed to keep muscles warm.”

Tirado stressed the importance of workers staying hydrated, advising they drink just as much water as they do in the summertime.

“You can get dehydrated even though you don’t feel like you’re sweating. It’s a common mistake that happens. [People] don’t realize that heat escapes the body very quickly in the winter, and they get dehydrated that way,” he said.

What to know

OSHA and NIOSH recommend that employers train workers on the prevention, risks and symptoms of cold stress. That training should occur well in advance of winter weather. Quick, daily reminders also are helpful, Jacklitsch said, especially when the weather is particularly cold or inclement.

Frostbite – Frostbite occurs when skin and tissue freezes, and can lead to permanent damage, potentially leading to amputation in severe cases. Symptoms include numbness, tingling, aching, blistering, and skin that feels firm or hard. The skin also might look waxy and white, bluish or grayish-yellow.

Experts recommend that someone suffering from frostbite be taken to a warm place as soon as possible, and co-workers on the scene should alert medical personnel. Unless necessary, a person with frostbitten toes or feet should not walk.

If outside, workers can protect frostbitten hands by putting them in their armpits, or they can cover their face, nose or ears with a dry, gloved hand.

Other first aid tips:

  • Remove any clothing or accessories that might hinder circulation. However, wait until you’re indoors to doff wet clothing.
  • Use a loose, dry cloth to protect the frostbitten area until medical help arrives.
  • Don’t rub the affected area – rubbing could damage the skin or break blisters.
  • Don’t warm the frostbitten area with direct heat from items such as a lamp, stove or fireplace, as this can cause burns.
  • Don’t thaw the frostbitten area if it has the potential to freeze again.

For mild frostbite, rewarm the affected area with warm water (99° to 108° F) for 15 to 30 minutes, according to Mayo Clinic.

Hypothermia – Severe shivering is one of the first signs of hypothermia, which occurs when the body temperature drops to less than 95° F. Other symptoms include confusion/memory loss, slurred speech, coordination difficulties, slow breathing, irregular heartbeat and loss of consciousness. Emergency personnel should be called as quickly as possible, and wet clothing should be removed and replaced in a warm, dry shelter.

Experts also recommend:

  • Gradually warm the affected worker, starting with the core of the body (chest, neck and groin).
  • If the worker is conscious, give warm, sweet and nonalcoholic liquids.
  • Be prepared to administer CPR if the worker becomes unresponsive.
  • Once body heat returns, keep the worker – including the head and neck – wrapped in a dry, warm covering.

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. © 2015 National Safety Council

Mayo Clinic warns against trying to warm a worker’s arms and legs if he or she is suffering from hypothermia, as it can add stress to the heart and lungs. The clinic also advises against rewarming a hypothermia victim too quickly “such as with a heating lamp or hot bath.”

Trench foot – Warning signs of trench foot, also known as immersion foot, include red skin, tingling, numbness, cramps and blistering. NIOSH advises removing shoes and wet socks, drying the feet, and avoiding walking, which can further damage tissue.

Chilblains – Chilblains are caused when exposure to the cold damages the capillaries in the skin. Symptoms may include redness, inflammation, itching and potential blisters. Sufferers should avoid scratching the skin, which should be slowly warmed. Corticosteroid cream can relieve swelling and itching, and any blisters or ulcers should be cleaned and covered.

Angina – Cardiac issues can arise in the winter more frequently than in summer because there’s a seasonality to heart disease, said Dr. John Osborne, from Grapevine, TX-based State of the Heart Cardiology.

Breathing in cold air can cause angina, or chest pains, from the heart not getting enough oxygenated blood. Problems also can arise from lower temperatures constricting the blood vessels and the heart’s extra pumping from a worker’s exertion.

A winter bout of the flu can create a “pro-inflammatory” state in the body, Osborne said, and make blood vessels more prone to clotting. He added that, most often, problems in the heart are not heralded by sharp pain. It might feel like a discomfort that you can’t quite pinpoint.

“Usually, it’s more of a burning, a pressure, ache, a tightness, a heaviness,” Osborne said.

Also, watch for shortness of breath, nausea, and dizziness or lightheadedness.

“[Employers should] remind people of the symptoms they have to be looking out for and that it’s a time when they have to keep a close eye on their work buddies, make sure everyone is doing OK,” Jacklitsch said.

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