Environment Canada has issued this year's first heat warning for Toronto, and most of southwestern Ontario.
The warning comes ahead of the arrival of a hot and humid airmass expected to affect the region Tuesday afternoon. Humidex values are forecast to be near 40.
A cold front is expected to follow Tuesday night returning the region to near-seasonal temperatures for the rest of the week.
Environment Canada is reminding the public that health risks associated with extreme temperatures are greatest in older adults, infants and young children and people with chronic illnesses such as breathing difficulties and heart conditions. People are advised to stay hydrated.
