This is the time of year when employers in many parts of the continent should be making focused effort to protect workers against winter weather. Occupational safety and health regulators include environmental and ambient hazards among those that employers must consider as part of their “general duty” to protect workers against recognized hazards. Requirements cover potential harm from extreme temperatures including cold, as well as slippery surfaces and other hazards from frozen and melting snow or other precipitation.
Agency regulations cover many specified types of situations, and guidelines are available for more. For example, the U.S. Occupational Safety and Health (OSHA) is drawing attention to its “Winter Weather” webpage as a source of information. The rest of this note summarizes information from OSHA’s webpage and those of other occupational safety agencies.
How Cold Is Too Cold For Workers?
Cold forces workers’ bodies to work harder to maintain core temperatures and protect extremities. Whenever temperatures drop below normal and wind speed increases, heat tends to leave the body more rapidly. The agencies do not define “too cold,” and instead offer the sensible observation that temperature, humidity, wind chill, and duration of exposure all affect the degree of cold stress workers may experience (although the Centers for Disease Control and Prevention (CDC) note that hypothermia is a bigger risk in most situations colder than 40 oF). Workers’ levels of acclimatization to conditions also matters – are they working in a storm, during a cold snap, or in a period when they’ve had time to adjust to conditions (as a Californian, I’m likely to have more trouble adjusting than a Michigander)?
Different individuals respond differently to the same environmental conditions, so employers should consider members of their workforce individually. As noted by OSHA, individually-applicable risk factors that contribute to cold stress include:
- Wetness/dampness, improper dress, and exhaustion.
- Predisposing health conditions such as hypertension, hypothyroidism, and diabetes.
- Physical conditioning.
Activities also matter. In general, an active individual (chopping trees and removing obstructions after a storm, for example) will generate more body heat than someone who is more sedentary.
How Can Cold Stress Be Managed?
Agencies provide the following general guidance for management of cold stress:
- Training
Employers should train workers how to prevent, recognize and respond to cold stress. Training should cover the following, as appropriate:
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- Cold stress and cold-related injuries and illness – symptoms and recognition (monitoring of self and others); first aid and medical/emergency assistance (including hypothermia, frostbite and trench foot), and how to apply first aid. Workers should be trained on the appropriate engineering controls, clothing and PPE, work practices, and controls.
- Other cold-related hazards – slippery conditions; unfamiliar situations, equipment, and activities; workplace air issues from heating
- Use of cold related clothing, personal protective equipment (PPE), equipment
- Engineering controls
Employers should provide engineering controls. For example, radiant heaters can be deployed to warm workers in cold locations such as outdoor security stations. Work areas should be shielded from drafts and wind to reduce wind chill.
- Safe work practices
Equipment. For work below the freezing point, metal handles and bars should be covered by thermal insulating material. Also, machines and tools should be designed for operation without removing mittens or gloves.
Clothing. Proper dress is extremely important to preventing cold stress. The type of fabric also matters. For example, cotton loses its insulation value when wet, but wool, silk and most synthetics do not. OSHA recommend the following for working in cold environments:
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- At least three layers of loose fitting clothing, including 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, and an outer wind and rain protection layer that allows some ventilation to prevent overheating
- Loose fitting so blood circulation is unimpeded
- Hat with ear covering, or hood (half or more of body heat loss is from the head)
- Knit mask to cover the face and mouth (if needed)
- Insulated gloves to protect the hands (water resistant if necessary)
- Insulated and waterproof boots (or other footwear) and warm socks
PPE. Protect against cold, as well as other physical, chemical or electrical hazards.
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- Face and eye protection. Select protective eye wear that is appropriate for the work, and for protection against ultraviolet light from the sun, glare from the snow, blowing snow/ice crystals, and/or high winds at cold temperatures. Especially in extremely cold conditions, eye protection should be separated from the nose and mouth to prevent exhaled moisture from fogging and frosting eye shields or glasses.
- Appropriate body and extremity coverings, gloves and footwear
Work plans and scheduling. Tailor workplace activities appropriately, including:
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- Work plans to identify hazards, safe procedures, and scheduling
- Communications, including visual/buddy as well as other appropriate
- Warming areas with warm liquids/food
- Tracking of weather conditions
- Acclimatization for new and returning workers
Safe work practices. For example,
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- frequent breaks, in warm areas
- allow (or even instruct) workers to interrupt their work if they are extremely uncomfortable
- pace work to avoid excessive sweating; if such work is necessary, provide proper rest periods in a warm area and allow employees to change into dry clothes
- provide warm-up time at the start of each work shift
- allow new workers and those returning after time away from work to acclimatize by gradually increasing their workload, and allowing more frequent breaks in warm areas as they build cold tolerance
- provide plenty of warm sweetened liquids to workers to prevent dehydration
- if possible, schedule heavy work during the warmer part of the day
- if possible, assign workers to tasks in pairs (buddy system), so they can monitor each other for signs of cold stress
- maintain walking and working surfaces to minimize slipping hazards.
Surveillance and Monitoring. The Canadian Centre for Occupational Health and Safety (CCOHS) recommends that every workplace where the temperature may fall below 16°C (60.8°F) should be equipped with a suitable thermometer to monitor further temperature changes. The temperature in workplaces with temperatures below the freezing point should be monitored at least every 4 hours. For indoor workplaces, whenever the rate of air movement exceeds 2 meters per second (5 miles per hour) it should be recorded every 4 hours. In outdoor workplaces with air temperature below freezing, both air temperature and wind speed should be recorded.
Emergency Procedures. Procedures should be established for providing first aid and obtaining medical care. For each shift, at least one trained person should be assigned responsibility to respond to cold-related emergencies.
Self-Assessment Checklist
Do any of the organization's workers work in situations where ambient temperature may create a hazard of cold stress:
- Outdoors (e.g., construction, utility, or post-storm work)?
- Indoors (e.g., work in refrigerators or in processes involving cryogenic materials or equipment)?
Does the organization conduct activities in areas subject to extreme cold weather, even if extreme conditions are not routine?
If so, does the organization provide appropriate:
- Training?
- Engineering controls?
- Equipment?
- Clothing and PPE?
- Safe work practices?
- Surveillance and monitoring?
- Emergency procedures?
Where Can I Go For More Information?
- OSHA Winter Weather webpage
- Centers for Disease Control and Prevention (CDC) “Winter Weather” webpage
- National Fire Protection Association (NFPA) educational documents:
- Canadian Centre for Occupational Health and Safety (COHS) Cold Environments webpage
About the Author
Jon Elliott is President of Touchstone Environmental and has been a major contributor to STP’s product range for over 30 years.
Mr. Elliott has a diverse educational background. In addition to his Juris Doctor (University of California, Boalt Hall School of Law, 1981), he holds a Master of Public Policy (Goldman School of Public Policy [GSPP], UC Berkeley, 1980), and a Bachelor of Science in Mechanical Engineering (Princeton University, 1977).
Mr. Elliott is active in professional and community organizations. In addition, he is a past chairman of the Board of Directors of the GSPP Alumni Association, and past member of the Executive Committee of the State Bar of California's Environmental Law Section (including past chair of its Legislative Committee).
You may contact Mr. Elliott directly at: tei@ix.netcom.com