Toronto health officials upgraded a heat alert that began Sunday to an extreme heat alert. That means the city will be making cooling centres available at local community centres and libraries, while many city-run pools will be staying open later.

Temperatures Monday reached a high of 32 degrees Celsius in the city, with the humidex making it feel closer to 40 C, Environment Canada says. Tuesday's high is forecast to reach 33 C with high humidity.

"What we are seeing right now is almost what you would see in the dog days of summer," David Phillips, senior climatologist at Environment Canada, told The Canadian Press.

Parts of the city got a break from the hot weather as showers broke out during the day.

The average temperature for June 24 for Toronto is approximately 25 C.

The city first issued a heat alert on Sunday, as temperatures began to climb and eventually reached 32 C. The extreme heat alert was declared early Monday and will remain in effect until further notice.

Environment Canada has issued its own special weather statement for southern and eastern Ontario, warning of hot and humid air all the way to Montreal including parts of central Ontario.

"This is southerly air. It has lot of mugginess with it. It’s a sultry, oppressive kind of weather," Phillips said.

With Wednesday bringing a 70 per cent chance of rain, temperatures are expected to begin to fall later in the week.

"We may get down to something next weekend that is closer to four degrees colder than normal, like 22 C," Phillips said.

During an extreme heat alert, people are encouraged to check on family, friends and neighbours without access to air conditioning, especially vulnerable adults and children, to make sure they are keeping cool and drinking plenty of fluids.

People are also encouraged to seek shelter at air-conditioned shopping malls, libraries, community centres and civic building.

Family pets are welcome at cooling centres during extreme heat alerts, though they must be leashed or under the owner’s control at all times.

Road worker John Ciccarella is spending Monday helping to re-pave a street in suburban Whitby. He says the key is to take lots of breaks.

"We pace ourselves, don’t work too aggressively, you know" he told CTV Toronto. "It’s a long day so we stretch it out. We drink a lot of water. And whenever you get a chance to get a little shade, you take that chance."

Other tips on coping with the heat include:

drinking lots of cool water

taking cool showers or baths, or use cool wet towels to cool down

keeping blinds or drapes closed to block out the sun

cancelling outdoor activities or rescheduling them to cooler parts of the day

making meals that don’t use an oven, especially if you don’t have air conditioning

never leaving children or pets unattended in a car

Symptoms of heat-related illnesses include dizziness or fainting, nausea or vomiting, headache, rapid breathing and heartbeat. It’s important to seek shade and drink plenty of water if you begin to experience any of these symptoms.