Some rain is in the forecast today and will provide a short lived break from the hot weather.
But the heat warning is still in affect as humidex values of 40 are expected again.
Environment Canada says a cold front will slip through the area today but then the heat and humidity is back Tuesday and will continue for most of the week with temperatures climbing above 30.
The effects of heat illness include swelling, rash, cramps, fainting, heat exhaustion, heat stroke and the worsening of some health conditions.