And while the multiple days of triple-digit temperatures have made some people glisten and others drip, everyone seems to be seeking ways to dry off. Some are showering more or slathering on "clinical-strength" antiperspirant.
"Everybody is supposed to sweat to some degree," said Dr. Mark Krasna, a thoracic surgeon at St. Joseph Medical Center in Towson, Maryland, who performs the operation, called a thoracoscopic sympathicotomy. "It's one way the body regulates heat. But we all know friends or relatives who sweat more than others."
A normal amount of sweating is about an ounce and half a day, or enough to fill a shot glass. Those with excessive sweating, called hyperhidrosis, can produce four times that amount or much more. St. Joseph surgeons have treated a policeman whose hands were so slippery he had trouble handcuffing criminals and an orchestra conductor who struggled to hold a baton.
Though only 1 percent to 3 percent of Americans have the disorder, close to 12 percent of people in a recent survey by the International Hyperhidrosis Society reported that they sweat all the time and 15 percent say they sweat too much.
The amount has nothing to do with hygiene; rather it has more to do with heat, stress, genetics and some diseases and medications. Still, the wet T-shirt contest look can be off-putting to everyone from your boss to your date to the guy next to you on the bus. Extreme-sweating cases can be socially crippling.
The first line of defense for sweating is an antiperspirant that blocks the ducts of eccrine glands, the body's major sweat glands, which produce odorless water sweating. Deodorant, which does not control wetness, masks the odor produced by apocrine glands found mainly in the armpits, which are responsible for oily, smelly sweat.
The new clinical-strength antiperspirants have more of the active ingredient, most commonly aluminum chloride. That can add a few dollars to the cost, and not all doctors believe they work better.
Some say they are effective for some users and worth trying. One of them is Dr. Jeffrey Dover, president of the American Society for Dermatologic Surgery, who also contributes a skincare line to CVS pharmacy.
He recommends applying to a clean underarm at bedtime so it "settles in overnight and works even better than if applied in the a.m." If that doesn't work, he said, there is a prescription-strength product that has even higher levels of aluminum. It's called Drysol, but it can be irritating, he said.
Aluminum has come under fire from some scientists for its possible link to breast cancer because of the underarm's proximity to breast tissue and lymph nodes, though Dover and others do not think that the evidence is credible.
The cancer research and support organizations Susan G. Komen for the Cure and the American Cancer Society agree that there are not strong epidemiologic studies supporting the link. Conversely, they cite a large 2002 study finding no tie to antiperspirant or deodorant use or underarm shaving (which some believe allows aluminum to enter more easily through razor nicks.) Komen, however, has commissioned the Institute of Medicine to further study environmental links to breast cancer.
Some people, however, are allergic to chemicals in deodorants and antiperspirants, usually found in the "fragrance." Stop using it if a rash develops and see a dermatologist if it doesn't go away, said David M. Pariser, past president of the American Academy of Dermatology and a founding member of the International Hyperhidrosis Society.
For those whose sweating is overwhelming the products, or perhaps they have job interviews or a wedding coming, he said the next step is Botox, an injection of botulinum toxin commonly associated with treating wrinkles. It can have side effects such as weakness, and it can be pricey.
Both armpits costs about $1,000, said Dr. Ron Schuster, a Lutherville, Maryland, cosmetic surgeon. He said most patients are women and have their armpits treated, though they also use Botox on the soles of their feet. He said that the procedure is virtually painless and that the results last about six months.
"It can have a dramatic effect on what kind of clothing they wear and their general self-confidence around others," he said.
For the more excessive sweaters, other options are prescription oral medications and a treatment that involves placing a patient's hands and feet in trays of water where they are subject to a low electrical current for 20 minutes three times a week. That interferes with the nerves promoting sweat.
The last-ditch procedure for the worst cases of hyperhidrosis is surgery called thoracoscopic sympathicotomy, which snips the nerves that lead to sweating. Doctors say it's most effective on the hands and armpits but less so on other body parts and often comes with significant side effects, including irreversible compensatory sweating, which means sweating somewhere else even more.