Environment Canada has issued a heat warning for Toronto, as southern Ontario experiences a stretch of late-summer sizzle that could break a temperature record.

"It is going to be hot, it is going to be sticky across the GTA," said CBC meteorologist Jay Scotland Friday. "We're potentially seeing the warmest day of the year."

A high of 32 C is in the forecast for Friday. But with the humidity, it's expected to feel like almost 40 C at the hottest points of the day.

If the temperature does top 32 C, Scotland said it will break a Sept. 5 temperature record for Toronto that stretches back to 1945. It would also be the warmest day so far this year.

Environment Canada says the high heat can be a danger to anybody’s health, but noted in a statement Thursday that the following groups are more at risk:

  • Seniors, children and infants
  • People with chronic illnesses, including heart conditions and psychiatric illnesses
  • People who work outside
  • Those who exercise in the heat
  • Residents without access to air conditioning
  • Homeless people

To keep hydrated, Environment Canada says, drink water before you feel thirsty. 

The steamy temperatures aren’t expected to last long. Highs of around 22 C are expected for Saturday and Sunday. Evening thunderstorms in the forecast Friday could also take the edge off the heat.

"The hot weather is short-lived as cooler air is set to move in," said Scotland. "The cold front arrives this evening. That could spark off strong thunderstorms around the time that many red carpet events with TIFF are taking place across the city."