Health Watch -- Heat and Medicine

Health Watch is a Public Service of the Office of News and Publications and is intended to provide general information only and should not replace the advice of a medical professional. You should contact your physician if you have questions about any of these topics.

What can make a hot day even hotter for your body?

Hot weather can be hazardous. Getting overheated can lead to heat exhaustion or even heat stroke. The best way to avoid heat-related illnesses is to drink plenty of fluids and to keep yourself cool by staying out of the heat.

But some people are in even more danger from the heat. Doctors at UT Southwestern Medical Center at Dallas say some medications can intensify the effects of heat on the body.

Dr. Greene Shepherd, a UT Southwestern toxicologist, says antihistamines make heat even more dangerous. These drugs, which are found in over-the-counter allergy and cold medicines, make the body sweat less. They dry up the mucus membranes, which eases symptoms like runny noses, but that also makes it harder for the body to cool itself. Sweating is one of the body's ways of fighting heat, so you're more likely to overheat.

Another kind of medication that can be dangerous in the summer is diuretics, which are often found in diet pills. They cause the body to shed water faster, through either increased sweating or increased urination. That puts you at increased risk for dehydration on a hot day when you'd be sweating a lot anyway.

If you're taking any of these medications, you need to take extra care in hot weather. Avoid strenuous activities during the hottest parts of the day. Drink plenty of water. And be especially alert for the danger signs of heat-related illness, such as dizziness, weakness or confusion.


June 2004