MONTREAL - The number of deaths spiked in at least one Canadian city during this week's heat wave.

Authorities say the deaths in Montreal be may linked to the high temperatures during the heat wave -- which affected all of Central Canada.

But they stress that it's still too early to confirm any connection with the record-smashing temperatures.

There are, on average, 40 deaths a day in Montreal.

The number of deaths was 43 on Wednesday and it surged to 80 on Thursday, the peak of the heat wave, when the humidex factor was well above 40C.