In a basement in Manhattan, people are sweating. And—this may interest you—they’re naked. They’re sweating to detox, to lose weight, to improve their complexions, and to experience euphoria, and if you listen to purveyors of infrared saunas they’re going to achieve not only that, but also more. They’re going to improve their circulation, they’re going to relieve their pain, and they’re going to emerge from their tiny personal sauna boxes relaxed, all of their earthly stressors and pains and toxins, whatever they are, soaked up into a fresh white towel.

It sounds too good to be true, doesn’t it? Yes, it does. But as the adage goes: If it sounds too good to be true, it usually is exactly as good as it sounds, especially when you look closely at its nebulous claims. Or, wait—how does that adage go?  

Infrared saunas use infrared light to heat the body from within rather than the air from without, as a traditional sauna does. Because of this, the saunas are able to operate at a lower temperature, usually around 157 degrees Fahrenheit rather than over 200, while providing the same (science-supported) cardiovascular benefits. Infrared saunas claim the light penetrates skin more deeply than the heat of a traditional sauna, which leads to more sweat, which leads to a more abundant release of “toxins.”

The infrared craze has recently grown from a mostly-just-Los Angeles trend to a New York City-and-everywhere-else trend, and it is a favorite of the Kardashians, various Real Housewives, Dr. Oz, Gwyneth Paltrow, and Chelsea Handler. The saunas have been featured recently in Vogue, Thrillist, New York magazine, among many others, and they were the subject of a New York Times piece last August. The coverage is often credulous; surprisingly, the most skeptical stance I found was in a blog post on Equinox gym’s website titled “The Science Behind Infrared Saunas,” which compares their claims (many) against the science that supports their claims (essentially none). Still, the Equinox blog post comes to the same conclusion as the rest of the coverage: Sure, the claims that infrared saunas make are so far unverified, but … ehh … do it anyway.

For my infrared sauna experience, I visited HigherDOSE—that Manhattan basement I was talking about earlier. The spa currently has two locations in the city, and I visited the flagship, located in the basement of the Bowery’s Alchemist’s Kitchen. The space is dark, moody, and relaxed, and each of the small, individual rooms offers a jug of filtered, ionized, and alkaline water. I went twice, not because I particularly needed to go twice for this story, but because I was able to use this story as an excuse to go a second time. From the start it seemed like it might be bullshit, but I frequently pay money for bullshit, and I love it. For example, I followed my first sauna session with a $10 cup of juice.

HigherDOSE opened in 2016 and comes to us from Lauren Berlingeri, a holistic nutritionist and health coach, and Katie Kaps, a startup executive and entrepreneur. (The DOSE stands for Dopamine, Oxytocin, Serotonin and Endorphins.) They are self-professed “seekers of natural highs” who “believe the key to the ‘high life’ is found through next-level health therapies.” In a phone call, I asked what, in their opinion, was the greatest benefit of infrared saunas. Berlingeri said,

“The most profound thing it does is detoxify. Because it detoxes heavy metals, radiation, and environmental pollutants. That’s almost unheard of, especially with heavy metals. There’s actually no other really good heavy metal detoxifier, other than the infrared sauna. And then radiation, we’re exposed to so much radiation and we don’t even know it, like from airplanes, to computers, to outlets. So to be able to come in and detox from that is a benefit.”

We’ll come back to this.

The actual infrared sauna is a smaller room inside of your little personal room, and it comes enhanced with chromotherapy LED lighting (an informational booklet in the room noted that the green LED light can help heal cancer—incredible!) and an AUX input to play music through your sauna’s sound system. What music did I listen to? Great question, thank you. I listened to Brian Eno’s Ambient 1: Music for Airports, which was a great choice. Brian Eno is incredible infrared sauna music. The album is also what this writer listened to while reviewing HigherDOSE. Maybe Brian Eno’s next collection of ambient tones should be titled Music for Infrared Saunas, NOT That I Necessarily Endorse Infrared Saunas.

After pouring myself a glass of filtered, ionized, and alkaline water (the ionized and alkaline aspects of which are at best unnecessary), I took off my clothes, wrapped myself in a towel, lay down on the other towel that was provided inside of the sauna, and started to sweat. I continued to lay and sweat for the 45-minute duration of my stay. It was warm and relaxing. I love to relax and do nothing, especially when it is for work, and I love to sweat, especially when it does not involve any work.

The private sauna within your private room is quite soothingly private, unless you go in with another person, which is allowed. I asked Berlingeri and Kaps if they endorsed the idea of people having sex in the saunas and they said no, they did not. I asked why, then, doesn’t their website say, “No having sex in the sauna”? They said they didn’t want to give anyone any ideas. (I bet people have sex in there.)

Inside the sauna, you’re able to change the LED lighting with a remote, and you’re given a guide to the benefits of each color. I chose the cancer one (green), of course, to fix any cancer I may have; blue, to calm me; orange, for wisdom; and purple, in case I had cerebral spinal meningitis, for which the color is allegedly an “excellent remedy.” So far so good, when it comes to cerebral spinal meningitis. The feeling of the infrared sauna didn’t differ too wildly from any other sauna I’ve experienced, but I did feel comfortable staying inside for a much longer period of time than I have in others. I’m not sure, though, if this was due to the lower temperature, the magical lighting, the privacy, the Brian Eno, or the countdown timer on the wall, which made it feel like a challenge against which I refused to crumble.

According to HigherDOSE, infrared sweat is not just any old sweat. I’ll allow a quote from the website to explain. “Sweat induced from an infrared heat source is comprised of 20 percent toxins whereas sweat induced from traditional heating systems is comprised of 3 percent toxins. This is why it’s accurate to say infrared is 7x more detoxifying than traditional heat.” You may have noticed that, rather than provide a citation to prove why it is accurate to say infrared is seven-times more detoxifying than traditional heat, HigherDOSE opted for a mathematical rephrasing. Very tricky. One might also say that I am 100-percent beautiful and my enemy Susan is 50-percent beautiful, which is why it is accurate to say I am two-times more beautiful than my enemy Susan. I’m sorry, Susan, but, as you can see, that’s just the way it is.

I asked Berlingeri to elaborate on infrared’s advanced toxin removal. “It penetrates your body three-inches deep to pull toxins out of your fat cells, which is a big deal,” she said. “Normally when you sweat it’s a more superficial sweat. Not only that, but normally working out is one of the other big times people think they’re releasing toxins. But when your body is in ‘fight or flight,’ it actually doesn’t release toxins. It’s only when your body is in ‘rest and digest’ mode that it actually releases toxins. So that’s one of the key misconceptions about sweating and working out.”

This sounds wrong to me, but I’m not a doctor. So I spoke with Dee Anna Glaser, a dermatology professor at St. Louis University and the president of the International Hyperhidrosis Society. Hyperhidrosis is the medical term for “excessive sweating,” which basically means Glaser is a sweat expert. First I asked how she felt about the idea, in general, of toxins being released in sweat. “In general,” she said, “sweat can release some toxins and some chemicals, but that is not really sweat’s major job. The organs responsible for detoxifying our system are the kidneys and the liver. Those two do such a good job that, really, sweat doesn’t need to do that. So, for most people, sweating a lot does not detoxify them at all. Because the kidneys are doing it. Sweat’s main job is to keep us cool.”

But what about the idea that toxins aren’t released during “fight or flight”?  “There is something called the fight or flight response to the body. That’s definitely true,” Glaser said, in a way that was funny. “But I have not at all, in all my years as a physician, ever heard that your body doesn’t release toxins or things in ‘fight or flight.’” She explained that it’s true that “fight or flight” is meant to enhance core functions, like how well your brain is thinking, and how well you’re moving and responding to things. “But ‘fight or flight’ only lasts for so long. Your body can’t maintain ‘fight or flight’ for long periods of time. So I’m not sure that’s clinically relevant at all.” While it is possibly true that periods of very intense exercise can ignite the “fight or flight” response, it is not likely that running on a treadmill sustains that response—perhaps unless there is a tiger running behind you, on another treadmill.

About the 20-percent toxin number, Glaser offered, “I certainly have never heard of that.”

Following up with Kaps and Berlingeri, I asked if they could send me a link to the sweat study or other source HigherDOSE used in obtaining that 20 percent number. After a few more requests, Kaps got back to me with a link to this page on infraredsauna.com, highlighting this paragraph:

“These special saunas are believed to be more effective in moving toxins through the skin than steam saunas because in the far-infrared thermal system only 80 to 85 percent of the sweat is water with the non-water portion being principly [STET] cholesterol, fat-soluable [STET] toxins, toxic heavy metals, sulfuric acid, sodium, ammonia and uric acid. Using the skin as an essential aspect of chelation therapy is important and makes complete medical sense.”

Unfortunately, although we have been assured that this makes complete medical sense, this website does not reference a study, or provide any sort of evidence. The main page of the site sells Jacuzzi brand infrared saunas, though this specific “mercury exposure” page seems, oddly, to be a different site altogether. (The page later touts the benefits of detox foot patches, which are a scam.)

But HigherDOSE and Jacuzzi aren’t the only infrared sauna brands advertising this number. The 20 percent versus 3 percent distinction is a major selling point for almost all infrared heat retailers, and it’s typically offered without citation. In a few cases I found, though, there is a citation—a parenthetical neither quoting nor linking to anything, while seeming, at the same time, quite official: “(Widmaier, Raff, Strang & Vander).”

This refers to the textbook Vander’s Human Physiology: The Mechanisms of Body Function by Eric P. Widmaier, Hershel Raff, PhD, and Kevin T. Strang.  

I purchased a copy of Vander’s Human Physiology from Amazon and couldn’t find substantiation of the claim, nor could I find it by searching for key terms in a PDF of the textbook, which was easier and what I should have done first. But the textbook was very confusing. Maybe, I thought, the evidence was simply beyond my grasp. Rather than rely on my own reading of the text, I sought confirmation from those who I believed would know best: the authors.

I was able to reach Eric P. Widmaier, Hershel Raff, and Kevin T. Strang, through email. Is this claim substantiated by what is found in Vander’s Human Physiology? Maybe you would like to pause in your reading for suspense. OK. The answer is: No. They each told me that it is not. “We do discuss that sweat contains salt (sodium and chloride) that can represent a large loss of electrolytes with a large volume of sweat (e.g. exercising on a hot day),” Raff said. Very tiny amounts of lead, copper, and nickel do appear in sweat, but if you have dangerously high concentrations of these metals in your body it is probably best that you visit a hospital rather than an infrared sauna.

“I have no idea what those citing our textbook would be referencing,” Strang said. “Our book certainly mentions sweating as a physiological response, and that sweat contains [salt] and some ‘other’ substances. But we have no in-depth statistics about toxins.” Each doctor mentioned that it is possible research about this exists, but if it does, they have not seen it.

It’s nice to sit, be warm, and listen to Brian Eno. It’s nice to have nothing to do, and to be afraid to look at your phone because you’re worried that the heat might break it. And I did feel happier after being inside the HigherDOSE infrared sauna. On my way home I almost tweeted “I LOVE NEW YORK,” because I was overcome with joy and my love for New York. (Ultimately I decided against the tweet.) The feeling was similar to the endorphin rush you get after working out, only without getting, you know, most of the benefits of working out. My heart rate had increased, I had relaxed, my skin enjoyed a short-lived glow. It was nice.

But, as far as I can tell, it seems like that’s all you can say for sure about infrared saunas. They are nice. (Aside from how they lie to people about their health while stealing their money.)