At press time, at least 48 people have died in the aftermath of winter storm Jonas, so health experts across the country are warning folks about the link between shoveling snow and deaths from heart attacks, the Washington Post reports.

When you shovel snow during cold weather, your body gets really cold, which causes your blood vessels to constrict and blood supply to your vital organs is decreased. This means if folks already have heart problems, diabetes or high blood pressure, shoveling snow is not a good idea. The same goes for people who aren’t physically fit.

“If you haven’t been exercising and you haven’t been exerting yourself, this is not the time to start,” said Lawrence Phillips, MD, a cardiologist at New York University’s Langone Medical Center. “The amount of work that goes into shoveling snow is tremendous.… People will underestimate the amount of work they are doing.”

A recent study from Nationwide Children’s Hospital in Ohio found that an average of 11,500 snow-shoveling accidents occur every year in the United States. According to the findings, cardiac-related injuries accounted for about 10 percent of total accidents, and caused more than half of all snow-related hospitalizations between 1990 and 2006 and all of the more than 1,600 deaths.

If you must shovel, follow these tips so you don’t become a statistic: Dress warmly and cover your mouth, ears and extremities to maintain body heat; warm up with light exercise before you shovel; stay hydrated; pace yourself; and take frequent breaks. In addition, push the snow aside rather than trying to lift heavy loads of it, and don’t try to clear the white stuff away all at once.

Plunging temperatures and icy winds can also create a perfect storm for freezing injuries. Click here for more information on how to protect yourself in cold weather.