Sweat lodges, saunas, steam rooms and plastic sauna suits are all designed to do the same thing: make you sweat without exercising. But to what end?
Jon Schroeder sits in the sauna at the YMCA Carondelet Park Rec Plex for 10 to 12 minutes a few times a week after working out. To him, it just plain feels good.
"In the winter especially, it's nice to work up a sweat," said Schroeder, 68, of St. Louis. He says he has no idea whether it has any benefit beyond that.
Four months ago, self-help guru and best-selling author James Arthur Ray led more than 50 people into a makeshift sweat lodge near Sedona, Ariz., for a ceremony that he said would cleanse their minds, spirits and bodies.
By the end of the ceremony people were vomiting and passing out. Three of them died and 19 were treated for burns, dehydration, kidney failure and respiratory arrest. Recently, Ray was arrested and charged with three counts of manslaughter in connection with the deaths.
Medical experts stress that there's a lot of misinformation about the benefits of sweating.
Essentially, its function is to cool the body and that's it, they say.
"Don't believe everything you read or hear," said Dr. Dee Anna Glaser, professor of dermatology at St. Louis University. She's been studying sweat for years and chuckles when asked about the benefits of spending time in a sauna or spa.
There really are no medical benefits, she said. She added that the liver and kidneys do such a good job of ridding the body of toxins that there's almost none left for the sweat glands to purge.
"I think people find it relaxing because it causes you to sit for a moment, and the heat feels good and relaxation is not a bad thing," said Glaser. "But there's not a specific health benefit. You could probably sit on a couch in a nice quiet room and get the same benefits."
For people with certain skin conditions, sitting on a couch and chilling may be preferable to sitting in a sauna and sweating. Glaser discourages anyone with broken capillaries, melasma (discolored skin patches) and some types of acne to stay out of heat because it exacerbates those conditions.
"It also can break down collagen which gives skin thickness and fullness," she said.
Dr. Rob Poirier, clinical chief of emergency medicine at Washington University, hasn't seen any cases of heat exhaustion, heat stroke or death from steam rooms or saunas recently. Most people, he said, know when to get out.
But he believes sweat lodges should be regulated and required to have on-site medical personnel monitoring ceremonies like the one near Sedona.
"They want people to feel better and have periods of enlightenment and they do, they have visions," Poirier said. "But that's probably hallucinating. There's a very fine line between when you can bring them back. You need to have someone with a good understanding of heat exhaustion and heat stroke to know when to pull them out."
People will use saunas and steam rooms for years with no problems, because, like Schroeder, they use common sense. But, Poirier notes, steam rooms can pose a higher risk of dehydration than saunas, which provide dry heat.
"The more humid it is, the less you sweat," says Poirier. "Sweat evaporates to cool you. When it doesn't evaporate, such as in a steam room, there's no cooling going on."
He adds that people who take diuretics, such as Lasix, to treat high blood pressure, are more predisposed to dehydration and, in extreme cases, heat exahustion and heat stroke. So are people who are hungover from drinking too much alcohol.
"People who drink heavily the night before can be slightly dehydrated which is why you feel hungover," he said. "Anyone with not a lot of fluid in their body will be more prone to going into heat exhaustion or heat stroke. Plus you won't necessarily feel your body getting sick as quickly as it's experiencing it."