Cold Stress

An 8-Step Cold Stress Compliance Gameplan

Date First Published on SafetySmart Compliance: December 17th, 2013
Topics: Heat & Cold Stress |

A strategy for limiting workers' exposure to cold weather hazards, indoors or outdoors


etween 1979 and 2002, an average of 689 U.S. workers died as a result of exposure to extreme cold. Of course, construction, fishing, maritime, farming and other outdoor workers are particularly vulnerable; but what you may not realize is that cold stress deaths aren’t just a winter phenomenon; many of the workers who succumb to cold stress work in freezers, cold storage facilities and other indoor workplaces.

Here’s a look at the risks posed by cold stress all year-round and the 8 practical measures necessary to manage them.

Liability for Cold Stress

OSHA Cold Stress Requirements

Although it’s recognized as a work hazard, cold stress isn’t covered in any specific OSHA standard. But that doesn’t mean employers can ignore the hazard. The duty to protect workers—indoors or outdoors—from cold stress comes not from an OSHA standard but the so called General Duty Clause (GDC), Sec. 5(a)(1) of the Occupational Safety and Health Act.

The GDC requires employers to protect workers from other “recognized hazards” likely to cause death or serious bodily harm. Over the years, OSHA has made it abundantly clear that cold stress may be a “recognized hazard” covered by the GDC. (See, for example, OSHA’s Safety and Health Guide on Cold Stress.)

Compliance Game Plan: 8 Steps to Take

There are 8 basic steps to take to protect workers from cold stress:

Step 1: Assess the Danger of Cold Stress

The first step is to perform a cold stress hazard assessment. To identify cold stress hazards you need to understand that the human body functions normally when it has a “core” temperature of 98.6° F. Although 1° or 2° doesn’t generally make a big difference, if core temperature drops too low it can lead to problems such as:

  • Hypothermia, i.e., when the body loses heat faster than it can replenish causing body temperature to drop to 95° F or lower, which can cause death in extreme cases;
  • Frostbite, i.e., actual freezing of the skin which can lead to amputation; and
  • Trench foot, i.e., freezing of the foot caused by immersion in cold water or prolonged exposure to extremely cold air.

Step 2: Measure Cold Stress Exposure

The next step is to figure out if the environmental conditions of the work place create cold stress dangers. Degree of exposure to cold stress is based not on comfort but what’s called thermal comfort, or how the air actually feels to the worker since it’s how the air feels that determines the impact on core body temperature. Risk factors to consider:

  • Temperature: Consider not just ambient temperature as shown by the thermometer but how the air actually feels to the worker. Rule of thumb: If temperatures drop below 30° F, you have a potential problem.
  • Wet and Damp Conditions: Wetness chills the body and increases the risk of cold stress.
  • Wind and Wind Chill: The faster the wind, the colder a worker will feel. The combined effect of cold air and wind speed is called “equivalent chill temperature” (ECT) or “wind chill,” or the temperature the body actually feels.
  • Contact with Cold Surfaces or Water: Being in contact with something cold chills the body and increases a worker’s risk of cold stress.
  • Workers’ Physical Condition: Consider the age, weight, fitness and acclimitization, i.e., whether workers are used to working in cold conditions.
  • Movement and Exertion: Moving around and doing intense physical work warms the body while standing around allows the thermal conditions to drop body temperature more easily.
  • Clothing: Clothing can insulate the body, helping it maintain body temperature and ward off cold stress.

Step 3: Keep Cold Stress Exposure at Safe Levels

The key to controlling workers’ exposure is to figure out where the thermal comfort danger line is and ensure that workers aren’t exposed to such levels (or if they are exposed are only exposed for a short, safe period). Unfortunately, the OSHA guidance doesn’t specify how cold is too cold.

Best practice dictates limiting exposure to safe levels using Threshold Limit Values (TLVs), a measurement created by a nongovernment organization called the American Conference of Industrial Hygienists (ACGIH) to define the maximum exposure limits for cold.

Step 4: Monitor Exposure Levels

The next step is to use appropriate instruments to continually monitor temperature and wind chill levels to ensure that thermal conditions are within safe ACGIH TLV levels.

Step 5: Implement Engineering Controls to Limit Exposure

As with other hazards, the preferred method of protecting workers from cold stress is to adopt engineering controls to eliminate or reduce the hazard. In the context of cold stress, engineering controls would involve use of methods to change the environment to ensure that exposure is kept at safe TLVs including:

  • Heating systems to warm the air;
  • Space heaters to warm sections of the workplace;
  • Heated trailers or other warming stations where workers can take breaks to warm up.

Step 6: Implement Administrative & Work Controls to Limit Exposure

The next layer of controls to use when cold stress hazards can’t be eliminated or engineered away is to change how the work is done so that it’s safer. So called work and administrative controls for cold stress include:

  • Acclimatizing, or gradually getting workers used to working in the cold.
  • Scheduling cold outdoor work for the warmest hours of the day.
  • Giving workers lots of breaks so they can drink warm sweet drinks and soups.
  • Training workers how to recognize and respond to different kinds of cold stress.
  • Having appropriate first aid personnel, facilities and equipment.

Step 7: Require Workers to Wear Protective Clothing and PPE

The last line of defense, which should normally be used in combination with rather than in lieu of engineering controls, is to ensure workers have and use appropriate protective clothing and PPE. For cold stress, this would include dressing in layers and wearing:

  • Gloves;
  • Insulation under the outer layers of clothes;
  • Hats or hard hats to cover the head and ears;
  • Waterproof outer layers when working in wet;
  • Warm socks; and
  • Warm shoes.

Step 8: Provide Appropriate Cold Stress Training

A proper cold stress training program should include:

  • Knowledge of cold stress hazards;
  •  Recognition of predisposing factors, danger signs and symptoms;
  • Awareness of first-aid procedures for, and the potential health effects of, different forms of cold stress;
  • Workers’ responsibilities in avoiding cold stress;
  • Dangers of using drugs, including therapeutic ones, and alcohol in cold work environments;
  • Use of protective clothing and equipment; and
  • Purpose and coverage of any environmental and medical surveillance programs and why workers should participate in them.

Implementation Strategy: Create a Cold Stress Plan

One of the most effective ways to implement all these measures is to incorporate them into a Cold Stress Plan. There’s no such thing as a one-size-fits-all plan. Details of your own plans will vary according to your industry, facility type, work process, etc. But the Model Plan in the TOOLS section of the SafetySmart Heat and Cold Stress Compliance Center lays out the fundamental elements a basic plan should include and can be adapted for your own workplace.