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In her latest blog post, Beth Traynor looks at the impact of extreme heat in the workplace. A 2012 Labour Relations Board decision found that extreme heat can be an ‘Act of God’ and justification for sending employees home if there is a threat to their safety. Beth also discusses the importance of having employment policies that are in line with the WSIA’s ‘Humidex Based Heat Response Plan’. The recent heat wave caused any number of problems for residents of Southern Ontario. Among them were concerns about how to keep employees safe when temperatures rose and then stayed high in the workplace. Strictly speaking, there is no law setting out employer obligations in this situation. But the Occupational Health and Safety Act includes a general obligation for employers to take every reasonable precaution to protect a worker. So what’s a “reasonable” precaution if the temperature in your workplace rises along with the outside temperature? 

While they don’t constitute law, the Ministry of Labour and the Workplace Safety and Insurance Board have issued policies and guidelines on the topic, which are summarized in a “Humidex Based Heat Response Plan”. And as a practical matter, the wisest approach is for employers to follow the Ministry’s policies and guidelines to ensure that “reasonable” precautions have been taken.

While the Response Plan may look complex at first glance, the principles are simple. Employers should: develop a heat stress policy; train workers to take steps to prevent heat stress and to recognize the symptoms if they do occur; keep track of the temperature and humidity in the workplace; and limit physical effort as the Humidex rises. For example, if an unacclimatized worker (someone not used to working in the heat) is performing moderately physical work, then when the Humidex rating in the workplace hits 38, she should have a 15-minute cooling break each hour. At a Humidex of 40, a 30-minute break is required. Where the Humidex rises to 42, workers should have a 45-minute break every hour.

It doesn’t take an MBA to figure out that productivity is severely hampered if workers are only active for 25% or 50% of their shift. That’s why some employers simply announce a layoff during the worst of a heat wave. It’s just safer all around.

There is support for this practice in the arbitral case law1. A heat wave has been characterized as an Act of God – an “overwhelming unpreventable event caused exclusively by the forces of nature”. Where the collective agreement provided that minimum reporting pay (four hours) was not guaranteed in the event of an Act of God, the employer was not required to pay employees for more than the actual hours worked (2.5) when they were sent home because of the heat.

Now that the heat wave has broken, workplaces are back to normal. But most experts agree that we’ll see more frequent extreme weather of all kinds in the future, so employers should be reviewing their policies to ensure that they are taking all reasonable precautions to keep employees cool.

1 Maksteel v CAW Canada, Local 252 (Call-in payment entitlement Grievance), [2012] OLAA No. 284

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