The coldest outdoor temperature ever measured on Earth was 128.6 degrees below zero Fahrenheit, recorded at a Soviet weather station in Antarctica. For the past two minutes, I've been standing in a small room that's nearly 100 degrees colder. In my underwear.

It's pretty cold. In fact, as the fog swirls around my bare legs and torso, it feels like it's getting colder, although that's a trick of perception; a computer makes sure the temperature in my dressing-room-size chamber stays steady at -220° F. Through a small porthole of triple-thick glass, I can see a seating area where a line of bathrobe-clad Angelenos patiently wait to take my place.

I'm at the offices of Cryohealthcare, a clinic in Beverly Hills that offers a procedure called whole-body cryotherapy (WBCT) to customers seeking relief from a host of different ailments, from wrinkles and sore muscles to arthritis and post-surgical pain. On a busy day, which this weekend morning is already shaping up to be, up to 100 people troop through these offices for a $65 treatment, among them more than a few professional athletes and Hollywood actors. The clinic has become so popular, its owners are opening up a second branch in Woodland Hills, and they're already eyeing Manhattan Beach for a third outpost.

Cryohealthcare is run by a physician named Jonas Kuehne, his wife, Emilia, and his brother, Robin. Jonas had first encountered WBCT in Europe during his medical residency; Emilia learned about it separately while working as a journalist in Germany. Together, they saw an opportunity to introduce it to the States, where it was virtually nonexistent, and purchased a unit for his family medical practice. "We were the first center offering whole-body cryotherapy," Emilia says. "There are a lot of places claiming they were the first, but we were actually the first."

At the time, among the only Americans who were hip to the benefits of WBCT were professional basketball players, many of whom had experienced it during stints in Europe. In 2009, a massage therapist who worked on several NBA players started referring them to Kuehne's clinic for cryotherapy. Word of mouth spread from there. Before long, teams started inquiring about buying their own units. The Kuehnes, by now offering cryotherapy full-time, established a second company, Cryomachines LLC, to manufacture them. A walk-in unit costs $98,000; a smaller one that chills only from the neck down runs $49,000. Ten NBA teams have purchased units, including the L.A. Clippers, Toronto Raptors, and San Antonio Spurs. (See my April 2015 Inc. magazine story about Hyperice, another cryotherapy company that caught on with the help of NBA stars.)

For pro athletes, three minutes in the "cryosauna" is a more palatable alternative to 20 minutes soaking in a tub of ice water. But physiologically, the two involve different mechanisms. With WBCT, explains Jonas Kuehne, "there's a shift in the pro- and anti-inflammatory protein profile, and you really only get that at cryogenic temperatures" of below -190° F. Cryohealthcare has to be careful about making medical claims, which need to be approved by the FDA, but abundant studies in Europe and Japan have established the efficacy of cryotherapy for pain management and other issues, Kuehne says, adding that orthopedic surgeons have recently begun referring patients to his practice post-surgery to manage their pain and swelling without opiates. 

This being Beverly Hills, of course, a lot of the clients who come through are looking at it less as a doctor's office visit than as a spa day. Cryotherapy supposedly tightens up the collagen in skin, and the whole-body variant is said to burn more than 500 calories at a pop. "A lot of clients need it for pain management, but they're more fascinated with the beauty aspect," says Emilia. (The Kuehnes themselves make quite a good advertisement for this aspect of their service: None takes fewer than three treatments a week, and all three look like models from a ski-resort brochure.)

The calorie-blazing and wrinkle-smoothing capabilities of WBCT don't interest me especially, but the muscle-recovery one does. At 38, skipping my ice bath after a hard soccer or tennis match means days of all-over soreness. "If you've done ice baths before, you're going to love whole-body cryotherapy," Emilia promises before steering me to a stall where I strip to my socks and underwear and don a bathrobe, gloves, clogs, earmuffs and a surgical mask, the latter to keep the supercooled air from singeing my lungs.

New clients are allowed to go into the cryosauna twice on a first visit. Before entering the chamber itself, I'm ushered into a small antechamber, a sort of airlock that keeps the temperature steady in the main chamber. I'm told I can request music to be played while I'm inside, but the music that's already playing -- "Sweet Emotion" by Aerosmith -- seems as good as any. I take a breath, open the interior door and step inside.

Emilia was right. Compared with plunging into an ice bath, this feels like nothing. The dry, unmoving air doesn't steal my breath the way frigid water does. As an automated woman's voice counts down the final seconds of my first 90-second exposure, I'm thinking, That wasn't so cold. As I step out, a tech measures my skin temperature: 45 degrees.

A few minutes later, I go in for my second spin: two minutes this time, Beyonce on the speakers. The extra 30 seconds makes all the difference. As I wait for the five-second warning, I can feel myself trembling. When the countdown reaches zero, I'm only too glad, and I even experience a brief moment of panic when I can't find the door handle in the fog.

And afterward? It's hard to say. I'd woken up feeling pretty good, so if there was any reduction in soreness, it was hard to detect. What I did notice was a sort of runner's high, a euphoria of excess energy that took two or three hours to wear off. Also, my wife told me my skin had a "glow." Based on the one-time results, I'm not about to pony up $98,000 for my own cryosauna, but if my gym had one of its own, I could see myself becoming a regular.