Outdoor Workers & Extreme Heat

July 2019 went down in the books as the hottest month ever recorded globally – a statistic that parallels climate trends in Canada.

A recent CBC story explored the topic of sun safety in outdoor workplaces–what regulations exist to protect people who work outside in extreme heat?  As it turns out, there are few concrete rules or laws in Ontario.

Ontario’s Occupational Health and Safety Act regulations do prescribe temperature minimums and maximums for a few particular settings involving freezers, compressed air, work chambers, and underground change rooms. But generally speaking, “[t]here are no set minimum or maximum temperatures for other workplaces.”

That said, according to the Ministry of Labour, extreme heat or cold can be a hazard and therefore “temperature is a legitimate issue in determining workplace safety. A particular concern is heat stress.”

Heat stress can be caused by working in outdoors in direct sunlight, in high humidity or hot enclosed areas such as commercial kitchens, laundries, foundries, factories, mines, etc. Heat stress can result in many types of illness ranging from rash and cramps to fainting, heat exhaustion and heat stroke.  It can also aggravate pre-existing cardiovascular and respiratory health conditions. Heat stress is dangerous and at its worst, can be fatal.

It’s important to note that while there are few explicit provisions related to extreme heat, employers and supervisors still “have a duty to take every precaution reasonable in the circumstances for the protection of a worker. This includes developing hot and cold environment policies and procedures to protect workers in hot and cold environments.”

In reality, this duty of care isn’t as clear as it could be. Ryerson occupational health professor Thomas Tenkate explains that “heat stress and its symptoms are not well defined under this duty of care, meaning a large number of business don’t take sun safety seriously because they aren’t legally required to. Legislation needs to be a more specific and with definable terms, or else it will continue to be ignored.”

One of the reasons that temperature guidelines are so vague is that calculating exposure limits is complex. Relative humidity, amount of air movement, work demands and clothing are all factors. The work-rest regimen and whether a person is acclimatized to the work load under the conditions are also important factors.

Still, with planning, policies and education, employers can manage heat and reduce the risk of heat-related injury or illness.

As our Canadian summers get hotter, more and more workers are likely to experience extreme heat conditions on the job. You have the right to a safe workplace, and you have the right to refuse unsafe work. To report unsafe work conditions, contact the Ministry of Labour Health & Safety Contact Centre toll-free at 1-877-202-0008. If you’ve been injured on the job and would like some advice, we are always here to help.