Snow is likely to mix with or change to sleet across parts of Pennsylvania on Sunday, the National Weather Service in State College said.

That will make it more difficult to clear snow off the driveways and walkways.

The weather service suggested shoveling snow periodically during the storm to make shoveling easier, instead of cozying up and waiting for the winter weather to subside.

But shoveling can pose health risks. Here’s how you can shovel safely, from the American Heart Association:

  • Start gradually and pace yourself. Instead of lifting or throwing the snow, push or sweep the snow off the sidewalks.
  • If something doesn’t feel right, stop. Don’t overdo it: Go gradually, and take breaks.
  • Bundle up. Layering clothes can form protective insulation for your body, but it’s also important to wear a hat or head scarf and keep your hands and feet warm.
  • Stay hydrated. Even though you probably won’t be sweating, thirst isn’t always the best indicator that you need to stay hydrated.
  • Look out for heart attack warning signs, including chest discomfort, shortness of breath and feeling tired, lightheaded or faint.

Strenuous activities such as shoveling snow can add stress to your heart that your body may not be used to. Your heart is also working extra hard to ensure a healthy body temperature.

Cold weather in general causes blood vessels to contract and coronary arteries to constrict, raising blood pressure and increasing the risk of heart attack, stroke or cardiac arrest.

Make sure to shovel periodically and safely.