Are There Workplace Temperature Regulations in Ontario?

Workplace temperature regulations in Ontario do not establish one universal minimum or maximum temperature for every workplace. Some workplaces do have specific requirements, including a general minimum of 18°C (65°F) for many enclosed workplaces covered by Ontario Regulation 851, but there is no single maximum workplace temperature that applies across Ontario.

Under Ontario’s Occupational Health and Safety Act (OHSA), employers have a general duty to take every precaution reasonable in the circumstances for the protection of workers. This means employers may need to address dangerous temperatures even when no specific temperature limit applies.

Understanding the difference between specific temperature requirements and general workplace safety obligations can help employers protect their workers and remain compliant. 

Is There a Legal Workplace Temperature in Ontario?

There is no single legal workplace temperature that applies to every Ontario workplace.

Ontario workplaces range from offices and warehouses to construction sites, commercial kitchens, refrigerated facilities, factories, and outdoor worksites. The temperature requirements and hazards affecting these environments can be very different.

Ontario does have specific temperature requirements for some workplaces. Under Ontario Regulation 851: Industrial Establishments, the temperature in an enclosed workplace must generally be maintained at a minimum of 18°C (65°F) during working hours.

However, the regulation includes several exceptions, including certain workplaces involving physical exertion, radiant heating, work outdoors or in freezers or coolers, and situations where the work process or product requires a different temperature.

The absence of a specific temperature limit does not mean an employer can ignore dangerous heat or cold.

Under the Occupational Health and Safety Act, employers must take every precaution reasonable in the circumstances for the protection of a worker. When temperature creates a potential hazard, employers need to assess the conditions and take appropriate precautions.

What Is the Difference Between Temperature Requirements and General Safety Obligations?

Specific temperature requirements establish a particular standard for workplaces covered by that regulation.

General health and safety duties are broader.

A workplace may not be subject to a regulation saying work must stop when the temperature reaches a particular number. Extreme heat or cold can still create a hazard that an employer is responsible for addressing. 

Temperature alone does not determine the level of risk. Employers may need to consider:

• Humidity

• Direct sunlight or radiant heat

• Wind and weather conditions

• Physical demands of the work

• Length of exposure

• Clothing and personal protective equipment

• Access to appropriate rest areas

• Whether workers are acclimatized to the conditions

These factors can make the same air temperature considerably more or less hazardous in different workplaces.

When Can Extreme Heat Become a Workplace Hazard?

Heat exposure becomes dangerous when the body has difficulty maintaining a safe internal temperature. 

Workers performing physically demanding tasks can experience greater heat strain than workers performing light work at the same temperature. Humidity, direct sunlight, limited air movement, protective clothing, and long periods of exposure can increase the risk further. 

Heat-related illnesses can include:

• Heat rash

• Heat cramps

• Dizziness or fainting

• Heat exhaustion

• Heat stroke (a medical emergency that requires immediate attention)

Heat can also contribute to other workplace hazards. Fatigue, dizziness, and reduced concentration can be particularly dangerous when a worker is operating machinery, driving, working at heights, or performing another safety-sensitive task.

When Can Extreme Cold Become a Workplace Hazard?

Cold stress can affect workers outdoors during Ontario winters as well as warehouse workers in refrigerated facilities, freezers, unheated buildings, and other cold environments.

Temperature, wind, moisture, clothing, physical activity, and length of exposure can all affect the risk.

Extreme cold can contribute to:

• Frostbite

• Hypothermia

• Numbness

• Reduced dexterity

• Loss of coordination

Cold can also make work more difficult. Reduced sensation and movement in a worker’s hands, for example, can interfere with the safe use of tools or equipment. Employers should therefore consider both the direct health effects of cold and the additional workplace hazards that cold conditions may create.

What Are Employers Responsible for During Extreme Temperatures?

Employers need to identify and address temperature-related hazards that could affect worker health and safety. The appropriate precautions depend on the workplace, conditions, work being performed, and the level of risk.

Ontario has published guidance for working in extreme temperatures within its safety guidelines for the film and television industry. While this particular guideline is industry-specific, it provides useful information about heat and cold stress and factors that can affect workers in extreme conditions.

Employers should assess the hazards present in their own workplace and determine which legislation, regulations, standards, and precautions apply.

Conditions should also be monitored as they change. Measures that are appropriate early in a shift may no longer be sufficient if temperatures, humidity, weather, or the physical demands of the work change.

How Can Employers Protect Workers From Extreme Heat?

The appropriate heat control measures depend on the workplace and degree of exposure. Practical measures can include:

• Providing access to cool drinking water

• Scheduling appropriate rest breaks

• Providing shaded or cooler rest areas

• Adjusting physically demanding work during periods of extreme heat

• Scheduling strenuous work during cooler periods where practical

• Improving ventilation or air movement where appropriate

• Allowing workers time to acclimatize to hot conditions

• Training workers and supervisors to recognize heat-related illness

• Establishing procedures for responding to signs of heat stress

Employers should pay particular attention during heat waves or sudden temperature increases because workers may not yet be acclimatized to the conditions. Outdoor industries, including construction, may require particular attention to changing weather and temperature conditions.

Workers should also know how to report symptoms or concerns and what to do if they notice signs of heat-related illness in a coworker.

How Can Employers Protect Workers From Extreme Cold?

Cold controls should similarly reflect the conditions and the work being performed. Depending on the workplace, precautions can include:

• Providing heated or sheltered rest areas

• Scheduling appropriate warm-up breaks

• Limiting exposure during severe weather

• Using suitable protective clothing where appropriate

• Keeping workers as dry as possible

• Adjusting work schedules based on conditions

• Monitoring workers for signs of cold stress

• Training workers to recognize frostbite and hypothermia

• Establishing emergency procedures for temperature-related illness

Wind chill is particularly important for outdoor work because wind can increase the rate at which the body loses heat. Wet clothing can also increase cold stress, making rain, snow, perspiration, and other moisture important considerations.

Should Employers Have Heat and Cold Stress Procedures?

Workplaces where workers may reasonably be exposed to extreme temperatures should have a practical plan for managing those hazards.

Procedures can establish:

• When additional precautions are required

• Who is responsible for monitoring conditions

• Required rest or warm-up and cool-down periods

• Access to drinking water

• Appropriate clothing or PPE

• Symptoms workers and supervisors should recognize

• How workers report concerns

• What to do during an emergency

The procedures should reflect the actual workplace rather than relying on a generic temperature policy.

Health & Safety Training is also important. Workers need to understand the hazards they may encounter, precautions they are expected to follow, symptoms of heat or cold stress, and how to report concerns. Supervisors should understand when conditions need to be reassessed and what to do when a worker shows signs of temperature-related illness.

Correct Compliance provides occupational health and safety consulting, including workplace hazard assessments, safety program development, workplace inspections, and policy and procedure development for Ontario employers.

What Should Employers Know About Workplace Temperature Regulations in Ontario?

The most important thing to understand about workplace temperature regulations in Ontario is that there isn’t one temperature limit that determines whether every workplace is safe or compliant. 

Specific temperature requirements apply in some circumstances. Where a specific limit does not apply, employers still have responsibilities under Ontario health and safety legislation when extreme heat or cold creates a potential hazard.

Employers can protect workers by assessing temperature-related risks, monitoring changing conditions, implementing appropriate controls, establishing clear procedures, and ensuring workers and supervisors understand how to recognize and respond to heat and cold stress.

Correct Compliance helps Ontario businesses identify workplace hazards and develop practical safety programs, procedures, and training appropriate for their operations.

Contact Correct Compliance to learn about workplace hazard assessments and practical health and safety support for your Ontario business.