Dr. David McKeown declared the heat alert will be in effect until further notice.
Under the advisory, Torontonians are reminded to stay cool and hydrated by drinking plenty of fluids, even if they don't necessarily feel thirsty. Residents are also encouraged to check on vulnerable people who may suffer from heat-related illness, such as children and isolated seniors.
Other precautions to beat the heat include:
- Staying in air-conditioned indoor areas such as shopping malls or community centres
- Avoiding the sun and staying in the shade
- Wearing loose, breathable clothing and wide-brimmed hats
- Rescheduling outdoor activities to cooler times of the day
Anyone with heat-related concerns can call the city's toll-free info line at 311.
The heat is expected to continue into Friday, which will also have a high of 30 C, according to an Environment Canada forecast. Temperatures are expected to dip slightly over the weekend, with a 70 per cent chance of precipitation on Saturday.