Get ready for what Environment Canada is calling the longest and most significant heat wave of the summer so far. Yet another heat warning has been issued for Toronto with afternoon temperatures expected to reach the low 30s with the added humidex values in the upper thirties to low 40s expected to start on Wednesday. Jane Brown will be speaking with Environment Canada’s Senior Climatologist David Phillips to find out what is causing this summer to be so hot, and provide us with some tips on how to keep cool during this extreme heat and, as always we’ll be taking your calls.