Environment Canada has placed Guelph, the Waterloo region and Wellington County under heat warnings since Wednesday.
The agency says that during daytime temperatures in the region are expected to reach 31 degrees Celsius and Humdex will approach 40.
Severe storms possible this week in southern Ontario as ‘very hot and humid conditions’ persist
Environment Canada says overnight temperatures are forecast to drop to just 20 degrees Celsius, with little respite in the evening.
The situation is expected to cool down a bit on Thursday, bringing some relief to the residents of the area.
The agency warned that hotter air could lead to poorer air quality and push the air quality health index into the high-risk category.
That agency said residents need to keep an eye on the effects of heat illness, which include swelling, rash, cramps, fainting, heat exhaustion, heat stroke and worsening of certain health conditions.
Environment Canada says people who need to cool down should seek shade, go to a swimming pool, take a shower or bath, or find an air-conditioned space.
It also states that you should never leave people or pets inside a parked vehicle for any length of time.
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