Many people underestimate just how strenuous shoveling snow can be.
And shoveling can trigger a heart attack in three ways. The increase in activity requires your heart to work harder. Also, without realizing it, you may hold your breath as you lift, which can trigger a sudden rise in heart rate and blood pressure. And cold weather causes blood vessels to constrict, so the heart has to pump more blood. If you have heart disease, you've got the makings of a heart attack.