FAMILY MEDICINE® COLUMN
By John C. Wolf, D.O.
Associate Professor of Family Medicine®
Ohio University College of Osteopathic Medicine

OLD MAN WINTER CAN CAUSE HEART ATTACKS, FROSTBITE AND HYPOTHERMIA

Question: Our winter hasn't been too bad so far, but I anticipate we'll get some snow soon. Each year I hear about people dying of heart attacks while shoveling snow. I am generally healthy, but I also have a strong family history of heart disease. Am I in any danger from shoveling snow?

Answer: There are many things which increase your risk of having a heart attack, a condition called a myocardial infarction (MI) in medical terms. Unfortunately, there is no completely accurate way of predicting who will have a heart attack, but personal and family medical history give us some clues. Since you have blood relatives with heart trouble, your chances of developing similar problems are increased. High blood pressure, smoking, obesity, diabetes and high cholesterol levels also raise the risk, but I don't know if any of these factors apply to you.

Shoveling snow is vigorous physical work, especially if the snow is heavy and wet. If you are accustomed to doing vigorous physical work, then shoveling snow is probably not excessively dangerous for you. But, you must exercise good judgment. Dress warmly, not just for the thermometer reading but for the wind chill as well. Shovel at a slow or moderate pace so that you don't place a great stress on your heart. When you are feeling a little tired, go inside and rest instead of forcing yourself to finish shoveling. The rest of the snow will still be there when you are rested and ready to shovel again.

An MI can occur during strenuous physical exertion like shoveling snow because the heart, along with your other muscles, is working very hard. If an area of the heart muscle is unable to receive adequate nourishment from the coronary artery which supplies it with oxygen-rich blood, the muscle will be damaged or perhaps even die. This damage is a heart attack.

The cold weather that accompanies snow poses other health risks. Cold temperatures can produce a temporary narrowing in the coronary arteries. If you have a coronary artery that is just barely large enough to supply the needs of your heart, this temporary narrowing may be enough to cause injury or permanent damage to the heart muscle.

Question: Are there any other dangers I should worry about?

Answer: Yes, I can think of at least two. First, there's frostbite, which causes damage to skin and underlying tissue. It affects the parts of the body that have become very cold, typically the fingers, toes, ears or the tip of the nose. In mild cases, the frostbitten tissue turns red and becomes painful when it is re-warmed. If the frostbite is more severe, the damaged parts may be painless but have burn-like blisters. In extreme circumstances, the tissue may actually die.

Second, a condition called "hypothermia" a potentially life-threatening decrease in body temperature is also common in cold weather. Normally, when your temperature falls below 98.6 degrees the body responds by shivering. This extra muscle activity produces more heat and increases the temperature of the internal organs. When you are cold, your body also slightly reduces the amount of blood that is pumped to the arms and legs. This likewise acts to warm the vital internal organs. Usually these normal body reactions are enough to keep the person alive until he or she can get to a warmer environment. However, if the body's temperature continues to drop, the person will become less active both physically and mentally. In the most severe cases of hypothermia, the cooling continues until death.

If you use good judgment, you should not have any of these problems when you shovel snow or engage in other outdoor activities in cold weather. In addition to the "common sense" guidelines I mentioned earlier, it's a good idea not to smoke tobacco or drink alcohol before or during your outside work because of their detrimental effect on circulation.

Family Medicine® is a weekly column. To submit questions, write to John C. Wolf, D.O., Ohio University College of Osteopathic Medicine, Grosvenor Hall, Athens, Ohio 45701.