With winter bearing down, it is a good time to familiarize yourself with the dangers of weather-related health threats and gain some important tips to help protect your workers from the cold weather. While the cold-weather months are obviously dangerous to employees spending long hours outside such as construction workers, other workers may be exposed as well. Remember, your employees may be conscripted to help out with shoveling out or other weather-related cleanup activities they do not normally handle.

What does the law say?

Although there are no regulations specifically addressing work in cold temperatures, OSHA’s general duty clause requires you to provide a safe and healthy workplace for your employees. Besides protecting your workers from expected threats like winter-weather exposure, you also have an obligation to rid your workplace of winter-related hazards like icy walkways and parking lots to avoid a citation under the general duty clause.

The science of cold weather

First, some science to help understand the dangers your workers will face. An individual gains body heat from food and activity, and loses it through convection, conduction, radiation, and sweating to maintain a constant body temperature. If the body temperature drops slightly below its normal temperature of 98.6°F, the blood vessels will constrict. This decreases blood flow to reduce heat loss from the surface of the skin. The body shivers to generate heat by increasing the body’s metabolic rate.

The environmental conditions that cause cold-related stress are low temperatures, high/cool winds, dampness, and contact with cold water. Wind chill, a combination of air temperature and speed, is a critical factor to evaluate when working outside. For example, when the actual temperature is 40°F but the wind is at 35 mph, it feels like 11°F to exposed skin. A dangerous situation of rapid heat loss may occur for someone exposed to high winds and cold temperatures even if it is not technically “freezing” outside.

The dangers of cold weather

Prolonged exposure to freezing or cold temperatures can result in serious health problems like trench foot, frostbite, hypothermia, and, in extreme cases, death.

• Trench foot is caused by long, continuous exposure to a wet, cold environment, including actual immersion in water. Work involving small bodies of water or working in trenches with water pose particular threats. Symptoms include a tingling or itching sensation, burning, pain, and swelling, sometimes forming blisters in more extreme cases.
  
  
• Frostbite occurs when the skin tissue actually freezes, causing ice crystals to form between cells and draw water from them. This typically occurs at temperatures below 30°F, but wind chill can cause frostbite at above-freezing temperatures. Initially, frostbite symptoms include uncomfortable sensations of coldness. A tingling, stinging, or aching feeling of the exposed area is then followed by numbness.
  
  
• Hypothermia occurs when body temperatures fall to a level where normal muscular and cerebral functions are impaired. While hypothermia is generally associated with freezing temperatures, it may occur in any climate where a person’s body temperature falls below normal. The first symptoms, which begin when the individual’s temperature drops more than one degree, include shivering, an inability to perform complex motor functions, lethargy, and mild confusion.

How to protect employees

Obviously, employers should watch for the symptoms described above, including uncontrolled shivering, slurred speech, clumsy movements, fatigue, and confused behavior. If you observe any danger signs, you should call for emergency help.

There are many methods to protect your employees from the cold, including protective clothing (e.g., gloves and hats), engineering controls, and common safe work practices. OSHA distributes a free “Cold Stress Card” with tips on handling cold weather.

Some tips include:

• Train workers about cold-induced illnesses and injuries;
  
  
• Encourage workers to wear proper clothing for cold, wet, and windy conditions including layers so they can adjust to changing conditions
  
  
• Be sure that workers take frequent short breaks in warm dry shelters to allow the body to warm up;
  
  
• Try to schedule work for the warmest part of the day;
  
  
• Avoid exhaustion or fatigue (because energy is needed to keep muscles warm);
  
  
• Use the buddy system – work in pairs so that one worker can recognize danger signs;
  
  
• Drink warm, sweet beverages (sugar water, sports-type drinks) and avoid drinks with caffeine (coffee, tea, sodas, or hot chocolate) or alcohol; and
  
  
• Eat warm, high-calorie foods such as hot pasta dishes.

Free copies of OSHA’s Cold Stress Card  in English and Spanish may be obtained through OSHA’s website. 

Remember that workers may face increased risk because of factors including age, medications, if they are in poor physical condition, or suffer from illnesses such as diabetes, hypertension, or cardiovascular disease. Other more obvious risk factors include wearing inadequate or wet clothing or having a cold.