DEAR DR. DONOHUE: I belong to a club that runs every day regardless of conditions. We run at least six miles. I am worried about running in hot weather and heatstroke. I have read that it can be deadly. I’ve brought this up to the 10 other runners, but they aren’t concerned. Will you give me some ideas of what to do and how heatstroke should be treated? – L.M.

ANSWER: If your club members have an iota of common sense, they and you should not suffer from heatstroke. It’s a rare occurrence, but it can be fatal. And it can happen at relatively cool temperatures if the humidity is high. I read of a case that took place at a temperature of 43 F (6.1 C) when the humidity was 99 percent.

Heatstroke is the result of heat production exceeding heat loss. It happens mainly to out-of-condition, unacclimatized people, including athletes, laborers and military recruits. You and your club members must be somewhat acclimatized by running daily, and you are in shape, but playing things safe is always wise.

Runners should stay hydrated. Dehydration increases the chances of suffering from a heat injury. If you’re running for more than an hour, you should be drinking water with some salt in it. If you want, you can use a sports drink.

Run during the coolest hours of the day – early morning or late evening.

If a runner feels woozy, that person should immediately stop, and a fellow runner should stay with him or her. If the runner isn’t making much sense, that’s a real danger signal. The brain is sensitive to a rise in body temperature. A rectal temperature of 105 F (40.6 C) signals great danger, and body temperature must be lowered quickly. That’s best done by immersion in cold water. A children’s wading pool is an excellent receptacle for this. The head and arms are out of the water. If this is impractical, then get the person to a hospital as fast as you can where it is air-conditioned and where intravenous fluids can be administered.

DEAR DR. DONOHUE: How should you treat sunburn? Are you supposed to put anything on the skin? I have heard it both ways. I have also heard that tanning is the best protection against sunburn. What do you think of that? – C.N.

ANSWER: Prevention is the best sunburn treatment. You can do that by staying out of the sun between 10 a.m. and 4 p.m., and by using sunblock when you are exposed to the sun.

Sunburn implies severe skin cell injury. The cells’ DNA is disrupted. That, in turn, leads to cell death and cell mutation, which sets the scene for skin cancer in the future.

Ultraviolet B rays contribute most to a sunburn. However, ultraviolet A rays age the skin. And both have a hand in promoting skin cancer. Some sunblocks now contain agents that deal with both kinds of ultraviolet rays. The sunblock should have a sun protection factor (SPF) of greater than 15, and it should be applied 15 to 30 minutes before going outside and reapplied according to label directions.

With a burn, the skin reddens in three to five hours after exposure, and the redness peaks in 12 to 24 hours.

Aspirin, Aleve, Advil or another nonsteroidal anti-inflammatory drug eases sunburn pain, and when used in conjunction with an over-the-counter cortisone cream, it can all but eliminate it. You can apply moisturizing agents to the skin. Aloe vera is a popular treatment. Cold compresses also help.

Tanned skin doesn’t burn. In acquiring a tan, skin cells are damaged, so tanning doesn’t produce a net gain in prevention.

DEAR DR. DONOHUE: Can you get sunburn from sun that comes through car windows? I believe it happened to me. – L.B.

ANSWER: Front windshields filter ultraviolet A and B rays, so they afford protection against sunburn.

Side and rear windows filter UV B but not UV A. Filtering UV B ought to check sunburn too.

DEAR DR. DONOHUE: I am 49, female and in good health. I do not take any medications. Several months ago, I developed an arrhythmia. My pulse would skip anywhere from once every four or five beats to once every 20 beats. I had no other symptoms.

A series of tests – including an EKG, an echocardiogram and a stress test – was all normal. My doctor informed me that this was not a concern, since we ruled out heart disease.

My pulse continues to skip beats. Is there anything else I need to do? – A.P.

ANSWER: Skipped beats are the most common heartbeat abnormality. Everyone has them from time to time. They aren’t “skipped” beats; they’re premature beats, ones that come before the normal scheduled beat. People don’t feel the premature beat. But after it, there is a delay until the next normal heartbeat occurs. During that delay, the heart fills with more blood than usual. When the normal beat arrives, the heart pumps out that extra blood, and the person feels it as a thud in the chest.

Premature beats originate in the upper heart chambers – the atria – and are premature atrial contractions (PACs), or in the lower heart chambers – the ventricles – and are premature ventricular contractions (PVCs).

So long as premature beats are not associated with any abnormal heart condition, they can be dismissed as not indicating current or future trouble. You have had a thorough heart exam. All your tests were normal. Your doctor feels that any more tests would be unnecessary. That’s a valid decision. Worrying about premature beats can be a greater health threat than the beats themselves.

Only if they increase in number or produce symptoms like feeling faint would further testing be of value to you now.

The booklet on heartbeat irregularities discusses the more common and serious kinds of arrhythmias. Readers can order a copy by writing: Dr. Donohue – No. 107, Box 536475, Orlando, FL 32853-6475. Enclose a check or money order (no cash) for $4.75 U.S./$6 Can. with the recipient’s printed name and address. Please allow four weeks for delivery.

Dr. Donohue regrets that he is unable to answer individual letters, but he will incorporate them in his column whenever possible. Readers may write him or request an order form of available health newsletters at P.O. Box 536475, Orlando, FL 32853-6475. Readers may also order health newsletters from www.rbmamall.com