Heat Stress: How Much Protection Does the Law Require?


Hopefully, now that summer is here, you’re warning your workers about heat-related illnesses (which, for simplicity’s sake, we’ll refer to collectively as “heat stress”) and pressing them to drink more water, take breaks, wear appropriate clothing, etc. That’s important. But is it enough? Are you confident that your workers are adequately protected? And if, heaven forbid, one of your workers were to die of heat stress, would you be liable? We’ll look at an employer’s liability risks for heat stress. And we’ll show you how to create a hot weather plan to protect your workers and insulate your company against legal risk.

Heat Stress & the Law

The first thing every employer needs to understand is that there is, without question, a legal duty to safeguard workers against the risks of heat stress. Seven provinces/territories (BC, NB, NL, PEI, QUE, SK and YK) include in their OHS regulations specific measures that employers must take to protect workers against heat stress. For example, Part 7 of the B.C. OHS Regulation requires employers to:

  1. Limit workers’ exposure to excessive heat;
  2. Conduct heat stress assessments to determine workers’ risk of hazardous exposure;
  3. Put into place a heat stress exposure control plan; and
  4. Implement engineering and administrative controls.

The laws of the other provinces don’t say anything specific about heat stress. But that doesn’t mean employers in those provinces get a free ride. On the contrary, every province has a General Duty clause that requires employers to take all reasonable precautions to protect workers against foreseeable risks that can cause death or great bodily harm. It would be hard to argue that heat stress is not such a foreseeable risk. So employers would be legally obligated under the General Duty clause to take reasonable measures to guard workers against heat stress.

But while the duty to guard against heat stress is clear, the exact measures required to fulfill that duty tends to vary by province. Still, the similarities are much greater than the differences. All provinces require at a minimum that employers train employees about heat stress and adopt policies and procedures for working in high temperatures.

Some of the “General Duty Clause” provinces that don’t spell out specific heat stress measures in their regulations do so in guidelines or special alerts. In essence, these guidelines explain what the General Duty Clause requires respecting heat stress. For example, the Ontario Ministry of Labour (MOL) has issued guidelines stating that Section 25(2)(h)—the Ontario version of the General Duty clause (which requires employers to “take every precaution reasonable in the circumstances for the protection of a worker”)—requires employers to “develop hot environment policies and procedures to protect workers in hot environments due to hot processes or hot weather.”

Employers Fined for Lack of Heat Stress Protections

Employers have been prosecuted for not doing enough to protect workers against heat stress. Two examples:

Ontario: Last year, a worker at a national bakery and food store died on the job from heat stress. The incident occurred on August 6, 2001, when southern Ontario was in the middle of a heat wave. With outdoor temperatures of 34 degrees Celsius, the temperature inside the bakery was 36 degrees. The worker overheated and collapsed. The MOL charged the employer with failing to implement a heat stress management plan in violation of Sec. 25(2)(h). The employer pleaded guilty and was fined $215,000 [Weston Bakeries Limited, Ont. MOL News Release, Feb. 18, 2004].

New Brunswick: In 1992, a boilermaker who worked for a repair contractor collapsed and died after three days of repair work in a paper mill. The outside temperature was 30 degrees C and the inside of the mill was even hotter. New Brunswick is one of the provinces that lists specific heat stress measures in its OHS laws (as opposed to relying on the General Duty Clause). The contractor pleaded guilty for not instructing the worker how to deal with heat stress dangers (in violation of Sec. 23(1) of the OHS Regulations) and was fined $7,500 [R. v. Lorneville Mechanical Contractors Ltd., [1993] N.B.J. No. 633].

How to Create a Hot Weather Plan

The Bottom Line: Telling your workers to be aware of hot weather hazards, take breaks and drink plenty of water is just part of what you need to do to prevent injuries and ensure compliance with OHS laws. You also need to create and implement a heat stress plan that combines appropriate engineering, administrative and work controls.

There’s no such thing as a one-size-fits-all plan. Details will vary according to industry, facility type, work process involved and the requirements of your province’s law. But, with the help of Tom Welton at the Ontario Forestry Safe Workplace Association, the Insider has created a Model Plan further below that sets out the elements a basic plan should include. Although designed for the forestry industry, the plan is easy to adapt for other kinds of operations, especially outdoor ones. Also keep in mind that these are minimum measures. Your province might require additional measures. For example, the plan doesn’t provide for medical monitoring which is mandatory in Quebec.

Like ours, your plan should:

Say When Heat Stress Measures Should Be Taken. Set a thermal trigger when heat stress measures should take effect. Several provinces, including BC, NL, PEI and Ontario, limit exposure levels based on the American Conference of Governmental Industrial Hygienist (ACGIH) standard. Quebec includes its own heat stress “schedule” in its regulations. And Saskatchewan and Yukon use subjective standards such as “reasonable thermal comfort” that aren’t measurable. If your province doesn’t specify a standard to use, you can use a humidex advisory, smog alert or temperature as your trigger.

Require Periodic Monitoring of Temperature and Humidity Levels. The legal obligation to protect workers against heat stress involves monitoring temperature and humidity levels. Some provinces, such as BC and Quebec, spell this out in their OHS laws. Others imply it. For example, PEI says employers must limit exposure to ACGIH levels. You can’t do this unless you monitor. So monitoring is required even though it’s not mentioned in the regulation. Welton suggests putting someone in charge of measuring the temperature and humidity levels at designated areas throughout your workplace.

Adopt Engineering Controls. Consider using engineering measures to control how hot your workplace gets including:

  1. Insulation and reflective heat barriers;
  2. Exhausting hot air and steam;
  3. Air conditioning;
  4. Using fans to keep air moving (provided that the temperature is less than 35 degrees); and
  5. Using machinery, such as hoists and lift tables, to make work less strenuous.

Adopt Administrative Controls. Your plan should include administrative controls such as:

  1. Assessing job demands and monitoring control strategies for hot days and workplaces;
  2. Longer and more frequent rest breaks;
  3. Scheduling strenuous job tasks for cooler times of the day;
  4. Providing cool drinking water near workers and reminding them to drink a cup every 20 minutes or so (Note: Providing workers drinkable water is required by every province);
  5. Limiting how long workers work in direct sunlight;
  6. Assigning additional workers or slowing down the work pace;
  7. Making sure everyone is properly acclimatized;
  8. Training workers to recognize the signs and symptoms of heat stress;
  9. Starting a “buddy system”; and
  10. Implementing first aid and emergency response plans for workers with symptoms of heat stress (another mandatory requirement).

Require Training. The plan should require training of all workers and supervisors about the signs, symptoms and prevention of heat stress. It should also describe the appropriate first aid measures for each form of heat stress, including heat cramps, heat exhaustion and heat stroke.

Require Appropriate Clothing. Your plan should also instruct workers to wear light summer clothing. If they work outdoors, they should wear light colours. It might be appropriate to require clothing for high radiant heat and water or ice-cooled insulated clothing for extremely hot temperatures.

Insider Source

Tom Welton, CRSP: Manager Field/Program Development, Ontario Forestry Safe Workplace Association; tomwel@ofswa.on.ca.

Hot Weather Plan

When the outside temperature reaches 30 degrees C or the humidex reaches 35 degrees C, Company’s Health & Safety Coordinator shall implement this Hot Weather Plan. All affected supervisors will be contacted to ensure they are aware of the proper procedures to be activated.

The Health & Safety Co-Ordinator or designate from the JHSC will measure the temperature as well as the humidity level at the following locations while the plan is active. These measurements will be taken at the beginning and halfway through the shift.

  • Slicer– Operator area
  • Log Washer – Operator area
  • Dryer – Infeed & Outfeed
  • Clipper  – Operator area and Trim tie
  • Log Yard– Chainsaw area
  • Sawmill– Log deck
  • Sawmill – Bander
  • Sawmill – Boardway piling lumber
  • Sawmill — Grader
  • Shipping – Bander
  • Log Yard — Garage
  • Maintenance – Shop

A record of these measurements shall be kept in the Human Resource office.

The following are control measures that will be implemented when this plan become effective:

Engineering Controls

  • Air conditioned rest areas
  • Fans and air bag to increase air movement
  • Full use of powered equipment – forklifts, transfer carts, cranes etc.

Administrative Controls

  • Provide extra workers when possible
  • Provide cool drinking water, as well as juice or Gatorade near work stations and remind workers to drink a cup every 20 minutes or so
  • Remind workers to salt their food (salt level drops in blood due to heavy sweating)
  • Provide training for workers and supervisors to recognize the signs and symptoms of “heat stress”
  • Encourage workers to wear light summer clothing to allow free air movement
  • Advise outside workers to wear light coloured clothing and sunscreen
  • Provide chainsaw operators a 5-minute break every hour in an air-conditioned rest area

An extra break of 5 minutes every hour will be given when the outside temperature reaches 33 degrees Celsius.

The Health & Safety Co-Ordinator shall ensure that all employees and supervisors will receive documented training which includes:

  • Signs and symptoms of “heat stress”
  • Prevention and control measures
  • Factors that could increase the risk of illness
  • First aid response

First Aid Response

If an employee is experiencing symptoms of “heat stress,” please follow these important steps:

  1. Take the employee to an air-conditioned first aid room, cool him down with cold compresses, and give him mildly salted water to drink.
  2. Contact the employee’s supervisor, who will ensure the employees’ safety by determining what heat stress illness or injuries are present.
  3. If the employee appears to be suffering from “Heat stroke,” call 9-911 immediately for medical assistance.

An employee who is suffering from a heat related illness must not be left alone.