Environment Canada has issued a heat warning for Guelph, Waterloo Region and Wellington County that is expected to last through Sunday.
On Thursday, the area is expected to see highs of between 32 and 35 C, with a humidex of between 35 and 38.
On Friday, the temperatures are forecasted to reach highs of 32 to 34 C with a humidex of 36 to 40.
A similar story will take place over the weekend as the area will see highs of 31 to 35 C, while the humidex could climb as high as 42 on Sunday.
There will not be a ton of relief overnight as Environment Canada says the overnight temperatures will only fall as low as 23 C.
The agency says the expected forecast could bring deteriorating air quality while warning that extreme heat affects everyone.
It says the risks are for young children, pregnant women, older adults, people with chronic illnesses and people working or exercising outdoors.
Environment Canada says to never leave people or pets alone inside a parked vehicle.
It says symptoms of heat illness include dizziness/fainting, nausea/vomiting, rapid breathing and heartbeat, extreme thirst and decreased urination with unusually dark urine.
Cooling centres will be available throughout Waterloo Region, Wellington County and Guelph.
Please check your local municipalities website for more details.