Huge swaths of Ontario and Quebec are under heat and humidity alerts, as the scorching summer weather slowly heads west.
Ottawa issued a heat warning for Friday and Saturday, with temperatures expected to reach 40 C or above with the humidex.
"The first tip we give people is: Pay attention to the signs your body is giving you and act on it," said Ottawa Paramedic spokesman J.P. Trottier.
"Typically, 911 is called for those who haven't paid attention to what their body is telling them."
It was 33 C with the humidex Thursday afternoon in the nation's capital, and around the city people were enjoying the afternoon sun.
Down the canal, the beach at Mooney's Bay was busy with sun-bathers, volleyball players and swimmers.
One volleyball player offered some advice: "Wear socks if you're on the sand for a long period of time so you don't burn your feet up. We learned that one the hard way," said Brandon, who was bashing around a volleyball with a few friends.
Toronto faced the second day of an extreme heat alert on Friday with temperatures hitting 39 C with the humidex.
A power outage affecting some 6,500 people downtown Thursday evening only made matters worse.
Environment Canada said the warm air mass is moving to parts of Southern Quebec, prompting heat and humidity warnings in Montreal and surrounding communities for Saturday and Sunday.
"The temperature will feel like 40 C with the humidex by the afternoon," said Gerald Cheng, a meteorologist at The Weather Network.
"The humidity will come down a bit on Saturday. Conditions will improve even further on Sunday."
An Environment Canada humidex advisory remained in effect Friday for much of south-central Ontario, including Toronto, Hamilton, Windsor, London and Ottawa.
Eventually, Western Canadians will feel the heat, too.
"I can see Edmontonians' smiles from here," said David Phillips, Environment Canada senior meteorologist, from his Ontario office. "From now to mid-August it's one word: Warm. And it may be the dress rehearsal for a hotter than normal summer."
According to Phillips, every day for the next four days will be warmer and sunnier than the next - and the city is expected to reach record setting highs for at least three of those.
The heat wave begins Saturday with the mercury skyrocketing to 29 C, Sunday is calling for 31 C but could easily blow the 1964 record of 31.7 C out of the water, said Phillips.
"We're almost certain we'll see a record-setting Monday - it's forecasted to reach 33 C," he said, adding the warm front won't stop there. "Good weather is here to stay."
Temperatures in the rest of the country Friday were in the low- to mid-20s, with the exception of 15 C in Whitehourse, 14 C in Labrador and 9 C in Nunavut.
- With files from Angelique Rodrigues and Marol Cameron