A heat wave in Quebec has killed 33 people in the past week as high summer temperatures scorched eastern Canada, according to officials.

Eighteen of the dead were reported in Montreal, according to regional public health director Mylene Drouin.

She added that the majority of the victims in the city were men aged between 53 and 85 living in vulnerable conditions and without access to air conditioning.

The rest of the deaths occurred in other parts of the French-speaking province.

Environment Canada forecast a maximum of 35C yesterday, with a heat index (what the temperature feels like to the human body) of up to 45C.

Montreal is in the grip of a heatwave which has hit countries across the world (Pic: Climate Reanalyser)

The heat wave was expected to end by yesterday evening with temperatures between 23C and 25C over the next few days.

"My thoughts are with the loved ones of those who died in Quebec during this heat wave," tweeted Prime Minister Justin Trudeau. "The record is expected to continue in central & eastern Canada, so make sure you know how to protect yourself & your family."

No deaths had been reported for the same period in the neighbouring province of Ontario, which has also sizzled under extremely high temperatures.

In 2010, a heat wave killed around 100 people in the Montreal area.