Health experts at the University of Kansas Hospital are warning people to avoid overtaxing their hearts while shoveling snow.

With a winter storm bearing down on Douglas County and the Kansas City metro area, the hospital said in a statement that people clearing snow should be alert to dizziness, extreme fatigue, faintness and chest pains. Cardiologists say that even people in relatively good physical shape can be at risk during cold winter days.

Cardiologists say the dangers for the elderly can be especially high. They urged people to work up to outdoor chores, such as snow shoveling. And health experts said that people with known heart disease should exercise only as part of a health program overseen by their physician.