Back to Basics is a weekly feature that highlights important but possibly overlooked information that any EHS professional should know. This week, we examine readiness for extreme winter weather hazards.
The Atlantic and Eastern North Pacific hurricane seasons just ended on November 30, and the first day of winter is December 21. In its U.S. Winter Outlook, the National Weather Service (NWS) noted the potential effects of a slowly developing La Niña weather pattern, which may include wetter-than-average conditions for the northern tier of the continental United States from the Pacific Northwest to the Great Lakes region, as well as northern and western Alaska, and drier-than-average conditions from the Four Corners region of the Southwest to the Southeast, Gulf Coast, and lower mid-Atlantic states.
La Niña conditions typically lead to a more northerly storm track during the winter months. The probability of wetter-than-average conditions is strongest in portions of Indiana, Ohio, and Kentucky, according to the NWS.
Are you ready for cold and winter weather workplace hazards?
Hazardous winter weather includes cold temperatures and hail, ice, snow, and a “wintry mix,” as well as extreme weather systems like nor’easters on the U.S. East Coast from September to April. Winter health hazards include carbon monoxide (CO) poisoning from the use of portable generators, fuel-burning space heaters, and other diesel- or gasoline-powered equipment, as well as chilblains and hypothermia, frostbite, and trench foot caused by exposure to cold and wet conditions. Injury risks include slips and falls on icy or wet walking surfaces.
Employees working in cold, wet, icy, or snowy conditions may be at risk for hazards like frostbite and hypothermia, as well as chilblains and trench foot. At a minimum, you schedule cold work for the warmest part of the day. On long-duration jobs, you may want to assign relief workers to limit individual workers’ exposure.
You should also be aware that the effects of cold weather can vary by region, and even worksites outside the country’s “snow belt” may experience cold weather hazards. In the Sunbelt and Southern United States, workers may be unaccustomed to winter weather. Even near-freezing temperatures that would pose little threat elsewhere in the country may present a risk.
Occupations in which workers face a risk of cold stress or injury include construction workers; farmers and farmworkers; firefighters, police officers, and other emergency responders; sanitation workers; and snow cleanup crews.
NIOSH, OSHA winter weather recommendations
The National Institute for Occupational Safety and Health (NIOSH) recommends that workers take commonsense precautions to protect themselves from cold weather hazards, which include:
- Wearing several layers of loose clothing, as layering provides better insulation, while tight clothing can interfere with proper circulation;
- Protecting their extremities—ears, face, hands, and feet—by wearing a hat, gloves, and waterproof boots;
- Carrying cold weather gear, such as blankets and a change of clothing, extra socks, gloves, a hat, and a jacket;
- Taking breaks in warm locations, such as inside a vehicle or a sheltered or heated area; and
- Monitoring their own physical condition and that of their coworkers for warning signs and symptoms of frostbite, hypothermia, chilblains, and trench foot.
Exposed limbs and the head are major areas of heat loss, so proper clothing is essential. A worker’s head and trunk should be warm enough to maintain circulation through the blood vessels in the hands and feet. Keeping blood flowing to the hands and feet is the key to preventing frostbite.
The Occupational Safety and Health Administration (OSHA) recommends that employers clear walking surfaces of ice and snow and spread de-icer as soon as possible after a winter storm to prevent slips and falls. The agency also suggests that workers take the following precautions following a winter storm:
- Wear proper footwear, such as insulated and water-resistant boots with good rubber treads, when walking on snow or ice during or after a winter storm is unavoidable.
- During winter months, keep a pair of rubber overshoes with good treads that can fit over street shoes.
- When walking on an icy or a snow-covered walkway, take short steps and walk at a slower pace to react quickly to a change in traction.
OSHA also has a hazard alert pamphlet, Snow Removal: Know the Hazards, providing employer guidance on preventing serious injuries and fatalities. The agency suggests that employers consider options to avoid work on roofs or elevated heights and make plans for safe snow removal. If snow must be removed from rooftops or elevated surfaces, employers should provide required fall protection equipment and training for those working on a roof or elevated heights and ensure ladders are used safely.
OSHA recommends that employers provide employee training on winter hazards, including the following:
- Cold stress—how to recognize the symptoms of cold stress and prevent injuries and illnesses, the importance of self-monitoring and monitoring coworkers for symptoms, and first aid and how to obtain medical assistance in an emergency;
- Other winter weather hazards—slippery roads and surfaces, windy conditions, and downed power lines; and
- Engineering controls, safe work practices, and proper equipment selection, including personal protective equipment, for winter weather protection.
Engineering controls to prevent cold stress include radiant heaters to warm workplaces like outdoor security stations and shielding work areas from drafts or wind to reduce wind chill. Aerial lifts or ladders can be used for safely applying de-icing materials to rooftops to protect workers from falling through skylights.
Additional safe winter work practices include the following:
- Scheduling work that exposes workers to the cold weather during the warmer part of the day;
- Using relief workers for long, demanding jobs;
- Limiting the amount of time spent outdoors on extremely cold days;
- Providing warm areas for use during breaks; and
- Monitoring workers at risk of cold stress.
While there’s no OSHA requirement that employers provide winter clothing, such as winter coats, jackets, gloves, parkas, rubber boots, and hats, many employers provide their workers with winter weather gear, such as winter coats or jackets and gloves.
The agency has additional safety tips on its winter weather webpage.
Alaska Occupational Safety and Health (AKOSH) recommends essential clothing for workers that includes thermal underwear, insulated footwear or mukluks with liners, double mittens, and a parka, preferably down-filled with a good ruff. A ruff offers additional protection against body heat loss.
Chilblains, frostbite, hypothermia, and trench foot
Working in cold temperatures poses several health hazards:
- Chilblains, or “chill burns,” are ulcers formed by damaged small blood vessels under the skin that can result from skin exposure to temperatures ranging from just above freezing to as high as 60 degrees Fahrenheit (F).
- Frostbite is an injury to a body part caused by freezing. It causes a loss of feeling and color in the affected areas and most often affects the nose, ears, cheeks, chin, fingers, and toes. It can permanently damage body tissue and, in severe cases, lead to amputation.
- Hypothermia occurs when the body begins losing heat faster than it can be produced. Prolonged exposure to cold eventually will use up all the body’s stored energy, resulting in hypothermia, which can be fatal. Hypothermia begins with uncontrollable shivering as a worker’s body temperature drops to 95 degrees F.
- Trench foot, or “immersion foot,” is a foot injury resulting from prolonged exposure to wet and cold conditions and can occur at temperatures as high as 60 degrees F if the feet are constantly wet.
Chilblains are caused when exposure to cold temperatures leads to damage to the capillary beds, the groups of small blood vessels under the skin. Redness and itching typically occur on cheeks, ears, fingers, and toes. The damage is permanent, and the redness and itching can return with further exposure to cold.
Workers need to wear several layers of loose clothing for insulation because tight clothing reduces blood circulation to the extremities. Their boots should be insulated and waterproof, and they should wear a hat to reduce the loss of body heat through the head.
Symptoms of chilblains can include redness; itching; blistering; inflammation; and, in severe cases, skin ulceration. If your workers experience chilblains, they need to slowly warm the skin, avoid scratching, and use corticosteroid creams to relieve itching and swelling. Blisters and skin ulcers need to be cleaned and covered.
Wet feet may lead to trench foot because wet feet lose heat 25 times faster than dry feet. When the feet are wet, the body constricts blood vessels to prevent heat loss, shutting down circulation in the feet. Skin tissue begins to die because of a lack of oxygen and nutrients and because of the buildup of toxins.
While the symptoms of trench foot may begin with numbness or reddening of the skin, it can lead to blisters or ulcers, bleeding under the skin, or even gangrene, which is when the foot may turn dark purple, blue, or gray.
You should have workers suffering from trench foot remove their boots or shoes and wet socks and dry their feet. They should also avoid walking on their feet, as walking can cause tissue damage.
CO hazards
Any tools or equipment that uses combustion to operate poses a risk of CO exposure. These include fuel-burning portable generators, space heaters, and compressors, furnaces, gasoline-powered forklifts and other motorized vehicles, power tools, pumps, and welding equipment.
OSHA recommends that employers install effective ventilation systems, avoid using fuel-burning equipment and vehicles in enclosed or partially enclosed spaces, and use CO detectors in areas where CO hazards may exist.
Ice, snow slips and falls
Ice formation and snow accumulation pose slip and fall risks. “Falls on the same level” cost employers $9.99 billion annually in medical expenses and lost wage claims, according to insurer Liberty Mutual’s 2024 Workplace Safety Index. Falls on the same level continue to be the top cause of losses for the leisure and hospitality industry and moved up this year to the third-leading cause of losses in construction.
“Slips or trips without a fall” cost employers $2.34 billion. Slips are caused by too little friction between workers’ feet and walking surfaces. Winter weather hazards like ice and snow can lead to a lack of friction.
Indoor workers may be at risk crossing employee parking lots, walkways (outdoor sidewalks, ramps, stairs, and stairways), and building entrances.
NIOSH recommends that employers place water-absorbent mats near entrances and other areas where water, ice, or snow may drip or be tracked onto floors.