Environment Canada yesterday forecast hot and humid conditions through Friday.
“Friday is expected to be extremely hot with humidex values reaching 40 for many areas. Minimum temperatures in the low 20s will provide little relief from the heat. Cooler temperatures are expected Saturday,” said an alert.
It said areas near the lakes can expect to remain cooler than areas inland.
Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high risk category, the weather agency pointed out.
It asked residents to watch for the effects of heat illness: swelling, rash, cramps, fainting, heat exhaustion, heat stroke and the worsening of some health conditions.
Drink plenty of water even before you feel thirsty and stay in a cool place. Check on older family, friends and neighbours. Make sure they are cool and drinking water. Never leave people or pets inside a parked vehicle. Outdoor workers should take regularly scheduled breaks in a cool place, it advised.