If you’ve been considering whole body cryotherapy (WBC), you might want to give it a second thought. The FDA has issued a consumer update about whole body cryotherapy. The update states unequivocably that whole body cryotherapy not been proven to be effective in treating or curing any of the conditions or diseases for which it is often recommended. No devices or treatments for WBC have received FDA approval.

Aron Yustein, M.D., medical officer in the FDA’s Center for Devices and Radiological Health said, “Based on purported health benefits seen in many promotions for cryotherapy spas, consumers may incorrectly believe that the FDA has cleared or approved WBC devices as safe and effective to treat medical conditions. That is not the case.” During a whole body cryotherapy session, people are either in a fully enclosed space, possibly along with others, or in an individual enclosure open at the top so the head is outside but the rest of the body is exposed to extremely low temperatures ranging from -200 to -300 degrees Fahrenheit. Sessions typically last from two to four minutes.

Professional athletes, entertainers, and celebrities are often cited as proponents of whole body cryotherapy, but the FDA is clear that people with any condition for which it is recommended should first consult with their physicians. The FDA is concerned that patients “may experience a lack of improvement or a worsening of their medical conditions.”

In considering issues on what happens to various body systems and organisms during a two to four-minute whole body cryotherapy session, FDA scientific reviewer Anna Ghambaryan, M.D., Ph.D. said, “We simply don’t know. At this time, there’s insufficient publicly available information to help us answer these questions. Potential hazards include asphyxiation, especially when liquid nitrogen is used for cooling.” There are also concerns that people could lose consciousness or suffer from frostbite, burns, and eye injury from the extremely low temperatures.

So if a trainer, wellness practitioner, or even your best friend suggest whole body cryotherapy, you might want to check with your doctor first. And be wary.