Environment Canada says it's going to be hot and humid across Sarnia-Lambton over the next couple of days.
The national weather agency issued a heat warning for the region on Tuesday afternoon.
It said a heat event is expected on Wednesday and Thursday, with daytime high temperatures expected to reach 32 to 35 degrees Celsius, beginning Wednesday afternoon.
Humidex values are forecast to be in the low to mid 40s.
Overnight low temperatures are expected to be 22 to 25 degrees Celsius, providing minimal relief from the heat.
The hot and humid conditions are expected to persist into Thursday, with conditions improving Thursday evening.
We're urged to check the Air Quality Health Index as it could approach the 'high risk' category.
Environment Canada said the risks are greater for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.
We're advised to drink plenty of water even before we feel thirsty and stay in a cool place.
