Many people aren't conditioned to the physical stress of outdoor activities and are unaware of the potential dangers of being outdoors in cold weather. Children, the elderly, and those with heart problems are especially at risk of developing problems from the cold, which puts an extra strain on the heart. If you have heart disease or high blood pressure, you need to follow your doctor's advice about shoveling snow or performing other hard work in the cold.
Cold constricts blood vessels that raise blood pressure, and when you repeatedly shovel snow or perform other strenuous winter outdoor activities, your blood pressure can rise dramatically. High blood pressure makes your heart work harder to circulate blood. If you are healthy and your heart is strong, this is not a problem.
But, if your heart and cardiovascular system are weakened and you're in poor health, strenuous activities can be overwhelming. Always follow your doctor's advice about shoveling snow or performing other activities in the cold. It is also important to listen to your body. If you are straining, you need to stop.
Remember when you are doing heavy outdoor chores, you need to dress warmly and work slowly. Your body is already working hard just to stay warm, so don't overdo it.