There isn’t enough evidence that whole-body cryotherapy is safe and sometimes it can be risky, Reuters reported.

The trendy procedure that exposes the naked body to subzero temperatures is advertised by spas and gyms as a way to treat sore muscles, back pain, and skin problems. But it can be risky, doctors warn.

A report in the Journal of the American Academy of Dermatology highlights a danger.

The paper reports a case of a 71-year-old man using whole-body cryotherapy who was severely burned when a nozzle malfunctioned and sprayed liquid nitrogen directly on his back for less than a minute. He had stinging, pain and redness, which developed into blisters with a yellow pus.

Cryotherapy procedure

Cryotherapy chambers engulf the body from the neck down in a liquid nitrogen mist at temperatures between minus-150 to minus 220 degrees Fahrenheit (minus-100 to minus-140 Celsius) for several minutes. The head stays above the top of the chamber.

Traditionally, dermatologists use cryotherapy to treat skin lesions such as viral warts, some skin cancers, and precancerous sun spots. Applied in very small areas by a trained physician, the liquid nitrogen freezes the skin and lesion.

Whole-body cryotherapy was originally given to patients with multiple sclerosis or rheumatoid arthritis for anti-inflammation effects. In recent years, it’s become popular for a wider audience.

Awareness of harmful side effects

With the rise of cryotherapy facilities and the ease that consumers can be treated, it’s important to spread awareness of the harmful side effects,” said coauthor Dr. Jordan Wang of Thomas Jefferson University Hospital, where the patient was treated.

Traditionally, dermatologists use cryotherapy to treat skin lesions such as viral warts, some skin cancers, and precancerous sun spots. Applied in very small areas by a trained physician, the liquid nitrogen freezes the skin and lesion.

Whole-body cryotherapy was originally given to patients with multiple sclerosis or rheumatoid arthritis for anti-inflammation effects. In recent years, it’s become popular for a wider audience. Proponents say the extreme cold helps muscle recovery after strenuous activity better than ice packs or cold water immersion.

Read about the case HERE.