Plenty of people will be shoveling snow Sunday, but doctors are reminding everyone to be careful.

Dr. On Chen is the director of the Coronary Care Unit and director of Outpatient Cardiology Services at Stony Brook Heart Institute. Chen says the extreme cold causes more demand on our hearts. Overexertion could cause arteries to restrict.

"Our heart rate goes up, the demand goes up, the supply is less just because that constriction of the cold air around," Chen says. "And that can precipitate a heart attack."

He also says everyone should take water breaks and dress appropriately while clearing themselves out.