Cryotherapy: How being exposed to Antarctica-like temperatures is surprisingly tolerable

The death of a spa worker in a deep-freeze chamber in Nevada earlier this week has seen the flourishing cryotherapy industry subject to intense international scrutiny.

The treatment – in which patients are subjected to temperatures as low as minus 140C – has enjoyed a recent upsurge in popularity driven by sports stars and celebrities including Mo Farah, Cristiano Ronaldo and Demi Moore.

But the discovery of 24-year-old Chelsea Ake-Salvacion frozen “rock solid” – after she entered a chamber unattended after work – has raised question marks over the procedure’s safety.

Developed in Japan in the 1970s to treat rheumatism and other conditions, cryotherapy is now sold on a host of health benefits – from healing surgical injuries to slowing down the ageing process.

There are only two permanent chambers in the UK, one at a medical facility in the Midlands and another at the BMI Healthcare Centre in Hendon. It is here that I trial the therapy, exposing my bare flesh to temperatures around minus 84C for a full three minutes.

Andy Streed, 34, physiotherapy lead at the BMI centre, compares the treatment to applying an icepack to an injury – except, of course, the whole body is plunged into extreme cold at once.

“The body basically goes into survival mode and concentrates on saving the organs,” he explains. “This means the core temperature warms up which leads to the blood picking up more nutrients and the muscle tissues kick-starting their restorative processes.”

While the BMI Healthcare Centre is a private facility, he estimates that half of patients treated here come through the NHS – while sports teams and athletes will occasionally book the facility for evenings and entire weekends.

The chamber is about the size of a shower cubicle and has a fine layer of snow-like frozen vapour covering the floor. It stands alongside a zero-gravity treadmill – which uses an inflatable plastic skirt to lighten a patient by 80 per cent, and a machine that builds muscles by zapping them with electrical currents. Despite being on the vanguard of medical technology, these machines have a distinctly Victorian flavour to them.

On their first visit, patients spend three minutes in the cryotherapy, eventually working their way up to six minute exposures. If they can bear it. One patient, confronted by the cold as the door opened, turned and walked out. A cloud of frosted air does indeed billow forth from the opened chamber like dry ice.

Wearing a hat, face mask, gloves, shorts, socks and Crocs, I step inside. An initial jolt is quickly followed by surprise at how tolerable the experience is – considering my half-naked body is exposed to a temperature just a few degrees shy of the lowest ever recorded in Antarctica.

When the three minutes are up, my fingers and toes are beginning to feel numb and my skin tingles. But I feel no real discomfort. I can barely believe it was as cold as the computer displays says it was.

Professor Clyde Williams, emeritus professor of sports science at Loughborough University, said that while the effectiveness of cryotherapy is not “clearly understood” its positive results when used immediately after sport probably resulted from “constricting blood vessels ... preventing the further leakage of proteins out of the muscle and into the circulation”.

But is it safe? Streed says he has no doubt that it is. He has never had a patient have an adverse reaction and only once cut a treatment short due to excessive shivering.

“First off, we always do a health check and look for past conditions that would rule you out,” he says. “We talk the patient through what to expect and explain they don’t need to stay in”

In the case of Ake-Salvacion, there is speculation that the liquid nitrogen used in the chamber may have debilitated her. But BMI’s facility uses a different cooling technique – reducing the air temperature with fans. Streed’s confidence in the safety of the treatment is supported by research. The main dangers associated with being subjected to extreme cold are hypothermia and frostbite. The threat of both is mitigated by the completely dry conditions in the cryotherapy chamber and the short period of exposure.