Daytime highs again will be in the low 30s with humidex near 40.
We could also see a cold front Monday afternoon, which will bring a cooler and less humid air mass.
As of Tuesday, according to CNN, an estimated 80 million people in the USA remained under heat advisories and warnings. The heat is going to continue until Thursday, with some relief on Friday when temperatures finally start dipping under 30 C. Besides the heat and humidity, Environment Canada is also calling for "very high" UV levels which means a higher risk of sunburn.
According to Environment Canada, the daytime high in Toronto will be 31 C on Tuesday, 32 C on Wednesday, and 32 C on Thursday.
A cool down is expected by Friday with the passage of a cold front.
Extreme heat affects everyone, Environment Canada said.
The heat warning extends throughout the GTA and most of southern Ontario, including Hamilton, Waterloo and Barrie.
To prevent heat stress during a heat alert, Dr. Strang suggests to stay in a shaded, cool or air-conditioned area, drink plenty of water, wear light-coloured clothing and to not leave anyone or any animal unattended in vehicles.
Isolated adults, seniors, young children, people experiencing homelessness and people with certain mental health illnesses, chronic illnesses, heart and lung issues or limited mobility are at greater risk of heat-related illnesses.
The national weather agency says humidex values will climb back up to 40 C or higher on Wednesday and Thursday.
There are many warning signs for heat illness, including swelling, rash, cramps, fainting, heat exhaustion, heat stroke and the worsening of some health conditions.