A heat warning has been issued for a large part of Ontario and Quebec, with the hot weather expected to last multiple days, Environment Canada reports.
Daytime highs of 30 to 35 C are expected with the humidex values of 35 to 40 C.
Overnight lows will be cooler but will still hover between 19 to 22 C.
Temperatures are expected to cool mid-week, which will start to bring an end to the heat, Environment Canada said.
The organization warns that extreme heat can affect everyone’s health and people should check on older adults, especially those living alone and other at-risk people.
Signs of heat exhaustion might include headache, nausea, dizziness, thirst, dark urine and intense fatigue.
Call 911 or your emergency health provider if you, or someone around you, is showing signs of heat stroke, which can include red and hot skin, dizziness, nausea, confusion and change in consciousness.
Environment Canada says heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion.