Summer is just beginning, but Ontario temperatures have already hit record highs. With these extreme temperatures, there has been a spike in heat-related workplace health and safety inquiries.
All sectors, industries and geographic regions of Ontario can be impacted by this hazard. We urge all employers to act now by learning about the hazard and the protections they should have in place.
What is heat stress?
Heat stress occurs when the body can't get rid of excess heat. When this happens, the body's core temperature rises and the heart rate increases. Left unchecked, heat stress can lead to heat exhaustion, heat stroke, heart attack, and other physical health effects.
Who can be impacted?
Any job that causes an individual’s body temperature to rise has the potential to cause heat stress. This means, every worker has the potential to be impacted depending on their work environment (e.g. air temperature, humidity, direct sunlight) or the duties of their job (e.g. physical activity, exposure to radiant heat or direct physical contact with hot equipment).
What are an employer’s obligations/legal duties regarding heat stress?
Employers have a duty under Section 25(2)(h) of the Occupational Health and Safety Act to take every precaution reasonable in the circumstances for the protection of the worker. This includes developing policies and procedures to protect workers who have direct physical contact with hot equipment, are exposed to radiant heat sources, or are working in hot weather. WSPS can assist businesses in creating policies.
For compliance purposes, the MLITSD recommends the current threshold limit value for heat stress and heat strain (published by the American Conference of Governmental Industrial Hygienists). These values are based on preventing unacclimatized workers' core temperatures from rising above 38ºC (100.4°F).
How hot does it need to be for heat stress to occur?
There is no specific temperature, but OHCOW’s Heat Stress Calculator and Response Plan provides some good guidance.
How heat impacts each person is different. Factors like age, health, fitness level, clothing and acclimatization can affect an individual's susceptibility to heat stress. Certain medications can also make a person more susceptible to heat-related illnesses, such as mood stabilizing medication, diuretics, (e.g. high blood pressure and fluid retention medications), antihistamines, stimulants and certain antibiotics can also increase the risk of heat-related illness.
What are the signs/symptoms of heat stress?
Early warning signs include sweating, excessive thirst, painful muscles cramps and darker urine – a sign of dehydration. A worker is in danger should they begin to experience the following:
- Fatigue
- Headache
- Light headedness/dizziness
- Fainting
- Nausea
- Vomiting
- Blurry vision
- Trouble focusing/confusion
- Excessive sweating or ceasing to sweat altogether
What should an employer include in a heat stress prevention program?
Although written for the film and television industry, what the MLITSD recommends to include in a heat stress prevention program would benefit any sector. (Ontario.ca)
The employer should implement a heat stress prevention program that establishes:
- worker training in the hazards, health effects and prevention of heat related illness.
- criteria or monitoring method (e.g. acting on heat wave or alert notices by Environment Canada or calculating humidex from temperature and humidity measurements or WBGT measurements).
- a monitoring/sampling plan (e.g. when, where and what to measure or monitor).
- responses or preventative measures (e.g. increase frequency of breaks, reduce the work pace and workload, avoid working in direct sunlight, schedule heavy work for cooler part of day, wear hat and sunscreen outdoors, etc.).
- a water supply plan and encourages hydration (e.g. at least 1 cup every 20 min.) and
- first aid and emergency responses, including monitoring of worker symptoms, and investigating incidents of health-related illnesses.
How WSPS can help
WSPS’ Building Blocks consulting solution can help you create your heat stress policies. Connect with a consultant, who can provide you with tailored guidance and resources, including templates for policies, procedures and forms.
General Heat Stress Resources
Agriculture-Specific Heat Stress Resources
- Staying safe in the field: Heat hazard management for farm workers and landscapers (article)
- Farm Safety Roundup - The heat is on: Protecting farm workers from the dangers of heat stress (podcast)
- Agricultural Safety Topic - Heat Stress (guide)
- 5 Tips for Heat Stress Prevention (NEW poster)
Restaurant/Kitchen-Specific Heat Stress Resources