Ah … those lazy days of summer! Sitting on the patio with a cold drink, soaking up some rays might seem like a great way to spend a day off, but what about those busy days of summer when you’re outside working hard in the scorching heat? Then the hot weather might not seem like such a gift.

When heat becomes a health issue

If you’ve ever been exposed to extreme heat, you probably know it can cause heat stress, with unpleasant symptoms such as rashes or cramps.

In more extreme cases, particularly if combined with physical labour, dehydration or a medical condition, the symptoms can be considerably more serious, including nausea, fainting and seizures. According to the Ontario Ministry of Labour, at that point it’s important to seek medical attention because those more serious symptoms, known as heat stroke, can be very dangerous, and potentially even fatal.

That’s why it’s a good idea to know how to protect yourself if you’re working (or playing!) in hot conditions.

Is heat stress just for summer?

Anyone can suffer heat stress if they’re exposed to extreme heat. And that could be at any time of year in a foundry or mine, for instance. But, for most of us, heat stress is a seasonal concern.

How much heat is too much? Summer heat risks

Everyone reacts differently to heat, so there’s no definitive answer to that question. However, here are some factors to consider:

    • Environment Canada issues a humidex advisory when the air temperature exceeds 30°C and the humidex (or humidity index) exceeds 40. The variables of heat and humidity are combined in the humidex to provide a ‘perceived temperature’ (much like wind chill in the winter).
    • Some people are more prone to heat stress than others, for instance those who have a medical condition, or are aged over 50.
    • It is possible to gradually acclimatize to higher temperatures, but the effects are temporary. Even after a weekend away from high temperatures, it could be necessary to re-acclimatize.

How to protect yourself against heat stress

Perhaps one of the best starting points is to know your own tolerance to heat. That way you can prepare if you know it’s going to be hot, and take a break if necessary.

Here are some other ways to stay safe when it’s hot outside:

    • Drink plenty of fluids, even if you don’t feel thirsty
    • Wear loose, light, breathable summer clothing. Long sleeves and pants are preferable.
    • Acclimatize to the temperature slowly, working shorter shifts at first and building up
    • Work in the shade if possible
    • Keep more strenuous tasks for the cooler parts of the day
    • Listen to your body, and watch out for signs of heat stress in others

To learn more about working in, and surviving, the extreme temperatures of summer, check out these resources: