Heat and wildfire smoke warnings are spreading across the country as a baking-hot summer shows no signs of letting up.

Alerts from Environment Canada stretched on Sunday from Regina through Winnipeg, across northern and southern Ontario, and into Quebec.

The most severe warnings are orange alerts issued around Winnipeg and Thunder Bay. Parts of northern Quebec are also under orange alert.

“A multi-day heat event continues for southern Manitoba lasting through Monday,” the warning around Winnipeg said.

“Temperatures exceeding 35 degrees are expected Sunday and Monday with humidex values in the mid 40s. Overnight lows will remain high as well, not dropping below 18 degrees.”

That area could hit 45 C when humidity is factored in.

Air quality warnings for wildfire smoke also blanket parts of Ontario.

In Oshawa, for example, residents are being told to limit outdoor time as a result of smoke drifting in from Quebec.

“Consider reducing or rescheduling outdoor sports, activities and events,” the alert said. “You may experience mild and common symptoms such as eye, nose and throat irritation, headaches or a mild cough.”

Whitehorse and Yellowknife are under yellow warnings for air quality.

The warnings come amid a particularly hot summer in Canada, as well as major heat waves in Europe, which just experienced its hottest June on record.