A huge snowfall can present a big heart attack risk, Ottawa paramedics are warning.

“Last Dec. 14 snowfall, Ottawa paramedics responded to three cases of heart attacks. The three males, one in his mid 40s the other two in their 70s, had been shovelling snow at the time of their attack,” said paramedic service spokesman J.P.Trottier.

A year before, paramed-ics responded to four cases of one of the deadliest types of heart attacks, called ST elevation in myocardial infarction. Again, the victims had been shovelling snow at the time of their attacks.