Public health authorities in Montreal say the heat wave that has blanketed southwestern Quebec since Wednesday has contributed to at least 10 deaths.
As a result, they are stepping up emergency measures.
Health officials are encouraging people to drink plenty of water and stay somewhere cool.
The city of Montreal has also extending opening hours for public pools and firefighters went door-to-door Saturday to make sure people are not in danger.
Saturday's forecast high is 27 C.
The temperature is expected to be in the mid–20s on Sunday.
On July 20, eight Quebec towns broke their own high temperature records, along with six in Ontario and two in Manitoba. The regions saw temperatures in the low to mid-30s, with humidex values in the 40s.