Environment Canada has issued a heat warning for Windsor, Essex County and Chatham-Kent.
The weather service expects temperatures and humidity to increase over the weekend. Maximum humidex values are forecast to approach 40 C on both Saturday and Sunday.
The unseasonably warm temperatures and humidity are expected to last into early next week.
Heat warnings are issued when very high temperature or humidity conditions are expected to pose an elevated risk of heat illnesses, such as heat stroke or heat exhaustion. Young children, pregnant women, older adults and people with chronic illness are most susceptible to heat illnesses.