More heat warnings have been issued for western Quebec and most of eastern Ontario, with cooler air not expected until Monday.
Environment Canada issued the warnings Thursday afternoon for areas including Ottawa-Gatineau, Renfrew and Lanark counties, Prescott-Russell and the Brockville and Cornwall areas.
Daytime highs around 30 C are expected, with humidity making it feel like the high 30s or 40.
Overnight lows should only drop to around 20 C.
Environment Canada recommends staying out of the sun during the hottest times of day, drinking water, checking on older people in your life and watching for signs of heat stroke.
Heat and humidity are expected to feel a slight bit cooler in the Bancroft, Belleville and Kingston areas.
There's a 30 per cent chance of showers in Ottawa Friday with the risk of a thunderstorm. Saturday and Sunday bring a 60 per cent chance of showers.