A heat event is expected to close out the summer holidays.
Environment Canada has issued a heat warning for Sarnia-Lambton, Chatham-Kent, Windsor-Essex, London-Middlesex, Elgin, Oxford, and southern Huron counties starting Sunday.
A hot airmass is expected to affect the area, bringing temperatures up to 35 degrees Celsius with Humidex values up to 40, until Wednesday. The hottest days are expected to be Tuesday and Wednesday.
"Hot and humid air can also bring deteriorating air quality and can result in the Air Quality Health Index approaching the high-risk category," the weather agency said.
Effects of heat illness can include swelling, rash, cramps, fainting, heat exhaustion, heat stroke, and the worsening of some health conditions.
There are increased risks for young children, pregnant women, older adults, people with chronic illnesses, and people working or exercising outdoors.
People are advised to drink plenty of water even before feeling thirsty and to stay in a cool place. Outdoor workers are urged to take regularly scheduled breaks.
