Cryotherapy may sound like something out of a science-fiction novel, but the procedure--little-known in the U.S., though popular in Europe--has been slowly making inroads among body-conscious consumers throughout southern California and, more recently, New York City.

For relief from minor aches and pains to physical trauma, so-called "whole body cryotherapy" is the practice of chilling the skin to just above freezing for approximately three minutes. It's essentially an ice bath on steroids, in which the cold decreases inflammation in joints and muscles. It can also help encourage the growth of healthy skin cells, and improve the dexterity of existing cells. Therein lies the opportunity of cryotherapy, a procedure whose origins date back several decades.

From serums and elixirs to peels and injections, the anti-aging industry is a gold mine that's only going to yield more riches as health-driven Millennials join Baby Boomers who refuse to take aging sitting down. By 2019, the anti-aging market will be worth $191.7 billion, up from the 2013 estimate of $122.3 billion, according to Transparency Market Research.

What's more, the practice already has a raft of celebrity clients who can help raise cryotherapy's awareness. Kobe Bryant has used it to assist his recovery from knee surgeries and postgame aches and pains; the NBA's Phoenix Suns have a team unit for players to use. Actors such as Jessica Alba and Jennifer Aniston use the treatment for the beautification that skin-cell renewal might provide.

The Big Chill

Joanna Fryben, the CEO of Kryolife, is betting that whole-body cyrotherapy will take off across the country. For starters, however, she'll settle for taking over the Big Apple. Her two-and-a-half-year-old company set up shop on 57th Street in Midtown Manhattan, with plans to open three additional locations in the tristate area in the coming year. For $90 a session or $700 for an unlimited pass, New Yorkers can experience the benefits of the icy therapy.

"There was no question in my mind: This is a perfect fit. New Yorkers do pay attention to quality," Fryben says. Eduardo Bohorquez, Kryolife Chairman, agrees. "You have diversity in the metropolitan area," he says. "And the average level of wealth, average income, is perfect for this type of treatment."

That doesn't mean Fryben doesn't have obstacles ahead of her. Chiefly, cryotherapy lacks Food and Drug Administration approval, which can be a deterrent for some consumers. There's also the education effort Fryben and other cryotherapy entrepreneurs must mount--because the term cryotherapy most likely makes people think of movie astronauts who go to sleep through light years of travel. You'd just be freezing yourself--and who'd want to do that?

"It's actually quite the opposite," says Fryben, who discovered cryotherapy in her native Poland when it was part of her mother's postsurgery physical therapy. "The cold just touches the body."

The process was invented in 1978 by Toshima Yamauchi, a Japanese medical doctor who was seeking a treatment for rheumatoid arthritis. Early therapies involved applying freezing instruments to small, targeted areas of a person's body, and the process has evolved over time.

Today, some patients are encased from the shoulders down in a cryosauna, a metal tube where temperatures drop to minus-256 degrees Fahrenheit. Others stroll into cryochambers, essentially walk-in freezers in which temperatures range from minus-112 to minus-180 degrees.

Cryotherapy's Claims

At its most effective, cryotherapists claim, the procedure triggers a fight-or-flight survival response that causes blood to temporarily leave the less important extremities for the body's core. The body prepares to fix any potentially damaged vital organs by pushing more oxygen, enzymes, and nutrients into the blood, and when the treatment is over, that enriched blood flows back into the rest of the body, accelerating cell renewal in tissues and skin.

Part of the fight-or-flight reaction involves boosting metabolic rates, says Jonas Kuehne, a medical doctor and co-founder of Hollywood's Cryohealthcare. So, he adds, the possibility of weight loss assistance is real. He's careful to put emphasis on assistance. "I would not promote it as a weight loss treatment, per se," he says. "But people, without changing really any parameters, do notice a very nice, gradual weight loss."

Kuehne, who graduated from the UCLA School of Medicine in 2003 and split his medical residency between the United States and Germany, explains that whole-body cryotherapy does cause the body to release endorphins, resulting in a temporary runner's high--but it's no magic depression cure. And while flash-freezing the skin and underlying tissue can be beneficial--even helping treat inflammatory skin disorders like psoriasis--cryotherapy won't be replacing Proactiv anytime soon. "You won't go within one treatment and see a dramatic difference," he says. "It takes some time."

Kevin Kramer, the co-founder and COO of the Roseville, California-based U.S. Cryotherapy, plans to stay away from such claims. Cryotherapy is purely an anti-inflammation mechanism, he says, noting that the treatment does nothing more than enhance circulation of oxygenated blood. For Kramer, who owns two locations in California, the discovery of the treatment came in 2009 through his father's neighbor in Prague, Olympic gymnast Denisa Baresova.

Testing Its Mettle

Yet like his counterparts, Kramer agrees that continued usage over time is ideal--six to 10 sessions are required to produce optimal results, he adds. "It's the way that it needs to be to really treat people to get the clinical outcomes that we're looking for," he says. "You just can't get it in two or three treatments, even though it's been hyped as such a treatment. It's not."

FDA approval will help people understand what whole-body cryotherapy does and doesn't do--but it's hard to predict a timeline for it. Much of the equipment used, Kramer says, already has European Medical Device Approval and UL listing--which means the FDA will really need only to replicate clinical work before clearing the procedure. He's not concerned about being denied certification.

"The medical community is very skeptical naturally, until there's FDA-approved indication and a vast body of clinical data and support here in the United States," says Kramer. "People just need to understand the processes, the mode of action, safety profile, those kinds of things that are really critical in the U.S. marketplace."