(CNN) High heat and humidity are to blame for the deaths of at least 17 people since Sunday in Quebec, according to Dr. David Kaiser of Montreal's Regional Public Health Department.

Kaiser told CNN Wednesday that the victims were mostly over the age of 50, male, and living alone. None had air conditioning, he said. Twelve deaths were reported in Montreal and five were reported in Eastern Townships.

CNN Meteorologist Taylor Ward said the region had seen record high temperatures and high humidity since Sunday. Temperatures were in the mid-90s for Montreal Sunday and Monday, about 20 degrees higher than the normal temperatures this time of year.

The heat index -- which is what conditions feel like with the humidity -- was above 100 degrees, Ward said.

Montreal health officials opened 19 cooling stations in public health and social services buildings across the city, and asked people to call public transport services to get a ride to one of the air-conditioned centers.

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