When it comes to workplace safety, it’s easy for most of us to think of safety in terms of PPE (Personal Protective Equipment) or the procedures associated with a particular piece of equipment or machinery. It’s also important to think about the impact the environment has on us. In these cold winter months, we should recognize how the cold can affect our health and safety.
Cold Stress is a real threat.
Anyone working in a cold environment may be at risk of cold stress. Some workers may be required to work outdoors in cold environments and for extended periods of time. A cold environment requires the body to work harder to maintain its core temperature. When the temperature drops below normal and the wind picks up; heat can leave your body more rapidly.
Cold stress occurs by driving down the skin temperature and eventually the core temperature. This may lead to serious health problems, cause tissue damage, and possibly death.
What are the risk factors that contribute to cold stress?
- Some of the risk factors that contribute to cold stress are:
- Dressing improperly
- Predisposing health conditions such as:
- Poor physical conditioning
How does the body react to cold conditions?
In a cold environment, most of the body’s energy is used to keep the internal core temperature warm. Over time, the body will begin to shift blood flow from the extremities (hands, feet, arms, and legs) and outer skin to the core (chest and abdomen). This shift allows the exposed skin and the extremities to cool rapidly and increases the risk of frostbite and hypothermia.
What are the most common cold induced illnesses/injuries?
What is hypothermia?
Hypothermia occurs when body heat is lost faster than it can be replaced and the normal body temperature (98.6°F) drops to less than 95°F. Hypothermia is most likely to happen at very cold temperatures, but it can occur even at cool temperatures (above 40°F), if a person becomes chilled from rain, sweat, or submersion in cold water.
What are the symptoms of hypothermia?
- Mild symptoms:
- An exposed worker is alert.
- He or she may begin to shiver and stomp the feet in order to generate heat.
- Moderate to Severe symptoms:
- As the body temperature continues to fall, symptoms will worsen and shivering will stop.
- The worker may lose coordination and fumble with items in the hand, become confused and disoriented
- He or she may be unable to walk or stand, pupils become dilated, pulse and breathing become slowed, and loss of consciousness can occur. A person could die if help is not received immediately.
What can be done for a person suffering from hypothermia?
- Call 911 immediately in an emergency; otherwise seek medical assistance as soon as possible.
- Move the person to a warm, dry area.
- Remove wet clothes and replace with dry clothes, cover the body (including the head and neck) with layers of blankets; and with a vapor barrier (e.g. tarp, garbage bag). Do not cover the face.
- If medical help is more than 30 minutes away:
- Give warm sweetened drinks if alert (no alcohol), to help increase the body temperature. Never try to give a drink to an unconscious person.
- Place warm bottles or hot packs in armpits, sides of chest, and groin. Call 911 for additional rewarming instructions.
What is frostbite?
Frostbite is an injury to the body that is caused by freezing of the skin and underlying tissues. The lower the temperature, the more quickly frostbite will occur. Frostbite typically affects the extremities, particularly the feet and hands. Amputation may be required in severe cases.
What are the symptoms of frostbite?
- Reddened skin develops gray/white patches.
- Numbness in the affected part.
- Feels firm or hard.
- Blisters may occur in the affected part, in severe cases.
What can be done for a person suffering from frostbite?
- Follow the recommendations described above for hypothermia.
- Do not rub the affected area to warm it because this action can cause more damage.
- Do not apply snow/water. Do not break blisters.
- Loosely cover and protect the area from contact.
- Do not try to rewarm the frostbitten area before getting medical help; for example, do not place in warm water. If a frostbitten area is rewarmed and gets frozen again, more tissue damage will occur. It is safer for the frostbitten area to be rewarmed by medical professionals.
- Give warm sweetened drinks, if the person is alert. Avoid drinks with alcohol.
How can cold stress be prevented?
Employers should train workers on how to prevent and recognize cold stress illnesses and injuries and how to apply first aid treatment. Workers should be trained on the appropriate engineering controls, personal protective equipment and work practices to reduce the risk of cold stress.
Employers should use safe work practices. For example, it is easy to become dehydrated in cold weather. Employers therefore, can provide plenty of warm sweetened liquids to workers. Avoid alcoholic drinks. If possible, employers can schedule heavy work during the warmer part of the day. Employers can assign workers to tasks in pairs (buddy system) so that they can monitor each other for signs of cold stress. Employers should give workers frequent breaks in warm areas. Safety measures, such as these, should be incorporated into the relevant health and safety plan for the workplace.
Dressing properly is extremely important to preventing cold stress. The type of fabric worn also makes a difference. Cotton loses its insulation value when it becomes wet. Wool, silk and most synthetics, on the other hand, retain their insulation even when wet.
The following are recommendations for working in cold environments:
- Wear at least three layers of loose fitting clothing. Layering provides better insulation. Do not wear tight fitting clothing.
- An inner layer of wool, silk or synthetic to keep moisture away from the body.
- A middle layer of wool or synthetic to provide insulation even when wet.
- An outer wind and rain protection layer that allows some ventilation to prevent overheating.
- Wear a hat or hood to help keep your whole body warmer. Hats reduce the amount of body heat that escapes from your head.
- Use a knit mask to cover the face and mouth (if needed).
- Use insulated gloves to protect the hands (water resistant if necessary).
- Wear insulated and waterproof boots (or other footwear).
Safety Tips for Workers
- Your employer should ensure that you know the symptoms of cold stress.
- Monitor your physical condition and that of your coworkers.
- Dress properly for the cold.
- Stay dry in the cold because moisture or dampness, e.g. from sweating, can increase the rate of heat loss from the body.
- Keep extra clothing (including underwear) handy in case you get wet and need to change.
- Drink warm sweetened fluids (no alcohol).
- Use proper engineering controls, safe work practices, and personal protective equipment (PPE) provided by your employer.
For more information, visit the Center for Disease Control (CDC) at