I received a call several months ago from a publicist for a company promoting an infrared sauna--a machine that is supposed to heat the body, not the surrounding air, and so produce sweat more efficiently. The company, Sunlight Saunas, contends that users experience the "same healing energy that is released naturally by the sun." On its Web site, it claims, as do abundant other Internet-based sellers of infrared saunas, an amazing list of health benefits: pain relief, weight loss, detoxification, increased circulation, cholesterol removal and a boost for the "immuse [sic] system."

The sauna is supposed to emit radiation in the infrared part of the spectrum, which adjoins the microwave spectrum. I started to imagine my body undergoing a gentle, slow cook without sunburn and without any of the icky cold parts that always remain in the middle when I heat up a frozen taco in the microwave. I knew that I could use a little detox, too--and not because I enjoy a glass of wine with dinner. Scientific American's offices on Madison Avenue are less than a block away from environmental monitoring equipment that measures the worst particulate levels in New York City (and some of the worst east of the Mississippi). The diesel fumes from the bus lanes there were an inspiration for an ad from the Natural Resources Defense Council that read "Standing behind this bus could be more dangerous than standing in front of it...."

An x-ray of my lungs could probably illustrate a medical pathology textbook. (My home, by the way, is near the heavily trafficked George Washington Bridge.) What the heck did I have to lose but some excess sulfates and other toxins? I first asked the publicist whether I could go someplace in the New York metropolitan area to sit in a Sunlight Sauna hot box. She said not to worry, the sauna would come to me. A week or two later a box almost big enough to sleep in arrived.

I'm someone who has never contemplated inhabiting any structure that does not come equipped with a superintendent. The thought of standing in a Home Depot aisle trying to distinguish between a ground fault circuit interrupter and a hinged single-pole breaker lockout induces abject terror. But even I could manage the assembly of the Sunlight Sauna Solo.

My spa was a space that stretched nearly underneath the desk in an unused windowless office. No Arizona desert vistas for me. Lying in the sauna, I stared up at a bank of fluorescent lights, my trunk and limbs covered by two cylindrical carbon shells. This personal sauna resembled a minimalist version of a computed tomography machine. I wondered how claustrophobes would do. The carbon shells emitted infrared radiation in the range of four to 50 microns. According to Sunlight Solo literature, the wavelengths coincide largely with those emitted by the body, heating it up at a lower temperature than can be achieved with a conventional sauna. Lying on an infrared heating pad allows for the warming sensation on all sides.

As advised by the publicist, I stayed in the sauna for 30 minutes. I gradually turned up the heat a notch every few minutes until it hit the highest setting of 150 degrees. By the end of the half-hour, my forehead glistened; I had drifted into momentary sleep a few times. When I stood up, I felt lightheaded but not dizzy. The relaxed feeling lasted the rest of the day. I tried the sauna three other times on different days. A colleague who saw me shoeless and in shorts and a Scientific American T-shirt inquired about how my "research" was going.

I asked myself: How does this sauna differ from all other saunas? I never came up with a good answer. How did it feel? Well, you could say that it was warm, calescent or maybe even thermogenic--in other words, caldo, chaud, heiss, or just hot, hot, hot.

I tried a sauna at the local YMCA to compare. I usually stay in for five minutes after going swimming at lunchtime but decided to stretch it out to half an hour to equal my time in the Solo. It still wasn't a one-to-one match, because the unadjustable sauna at the Y was more than 180 degrees against 150 for the Solo. Unlike the Solo, I had to leave the Y's sauna every 10 minutes or so to get a drink of water, and I didn't sweat quite as much. But I found that the same adjectives applied to what is essentially just another form of infrared energy. Any subtleties eluded me. I called Sunlight Sauna to ask what it is I should be feeling. Co-owner Connie Zack said that I might not notice any fundamental physical changes from taking a sauna unless I was actually experiencing some health problem, such as chronic back pain. [break]

The company had sent me two papers from the Journal of the American College of Cardiology on small Japanese studies: one showing improvements in vascular function in patients with chronic heart failure, another in patients with risk factors for heart disease. But the most far-reaching assertions for this technology center on detoxification. Claims for the ability of infrared saunas to rid the body of heavy metals and the like populate the Internet like Viagra ads. A press release for Sunlight Saunas mentions Dietrich Klinghardt, a Seattle-area physician who asserts that infrared saunas, but not conventional ones, rid the body of "cholesterol, fat-soluble toxins, toxic heavy metals, sulfuric acid, sodium, ammonia and uric acid."

A trip to Klinghardt's Web site turns up a document that states that sauna therapy can leach toxins from the body. But Klinghardt notes that the poisons can also be displaced from "one body compartment to another." Mercury (beware those old dental fillings) might shift from connective tissue to the brain, according to Klinghardt. That is, unless the patient ingests sufficient quantities of cilantro, garlic and chlorella (green algae) in conjunction with taking saunas. Oooo-kay. Needless to say, I didn't follow up by looking for references to this area of research in the National Library of Medicine. Sunlight Saunas also provided me with testimonials about the Solo's benefits from patients with Lyme disease, cancer and "general toxic overload."

I wasn't ready quite yet to go hunting down chlorella. I wanted to see what the allopathic (nonalternative) world had to say about detoxification. I called Roger Clemens, director of an analytical laboratory at the University of Southern California that evaluates environmental toxins in the food supply. Clemens remarked that the most efficient system for detoxification is not an infrared sauna but rather the kidneys, liver, gastrointestinal tract and immune system. "Except when one of the major organs breaks down, there isn't a medical device or any diet that can accelerate the body's natural process of detoxification," he says.

Hearing this, I decided I would rather rely on the multimillion-year track record of detoxifying my body by just going to the men's room. Shorn of health claims, the sauna was pleasant enough. But a moment of revelation came when I climbed into a car heated by the July sun. Once again, I felt a warmth indistinguishable from what I had experienced at both the Y and when I was wedged into the Sunlight Sauna Solo under the desk at work. Given the almost $2,500 total price for the sauna and the heating pad together, I wagered that I might be able to get the same benefits by spending less time looking for a parking spot in the shade. With a son in college, I don't think I'm going to take the big plunge for a Solo anytime soon.