A woman has been killed and another is fighting for her life after poisonous nitrogen leaked from a chamber during a cryotherapy session in Paris.
The 29-year-old victim was working at the On Air Voltaire gym in Popincourt when tragedy struck on Monday afternoon.
She and a 34-year-old client collapsed after nitrogen displaced oxygen in the ultra-cold chamber, which had been repaired earlier in the day.
The two women went into cardiorespiratory arrest when emergency services arrived at the gym shortly before 6.30pm local time, officials said.
Despite the efforts of paramedics, the staffer was pronounced dead at the scene, while the customer was taken to intensive care at the nearby Lariboisière Hospital.
Three other employees were treated for minor injuries and about 150 people were evacuated from the high-end gym.
On Air’s management said the building has been closed indefinitely, adding it was working with authorities “to understand what happened”.
Meanwhile, French prosecutors have ordered an autopsy and toxicological analyses of the victims.
Cryotherapy is a medical treatment that uses extreme cold to freeze and destroy abnormal tissue and cancer cells.
The body is exposed to temperatures as low as -140C (-220F) using liquid nitrogen and other substances.
Cryotherapy has become extremely popular with sports stars — including Floyd Mayweather and LeBron James — for its supposed health benefits, such as muscle recovery and increased blood circulation.
At least 17 spas, gyms and clinics offer cryotherapy in London, with prices starting from just £55.
However, cryotherapy has been labeled a controversial treatment due to mixed scientific evidence regarding its effectiveness and potential risks.
Liquid nitrogen, which is used to cool the chambers, can displace oxygen in the air if ventilation is inadequate.
Past incidents at cryotherapy chambers include suffocation, frostbite and severe burns.
The Mayo Clinic in Marleybone says research into the benefits of cryotherapy is “still in its infancy”.
They suggest a bag of ice on a swollen joint or sore muscle, or a swim in a cold lake, may be just as beneficial.
In 2018, the European Industrial Gases Association warned of the danger of nitrogen in cryotherapy, including the risk of “oxygen depletion and potential asphyxiation”.
