One person has died and another is in a critical condition following a nitrogen leak from a cold chamber during a cryotherapy session in the French capital, according to investigators.
The incident happened yesterday evening at a small sports centre located in the 11th district of Paris, a police source said.
According to initial findings, a nitrogen leak from the cryochamber is thought to have caused the poisoning, a source close to the investigation said. An employee of the gym, who was in her late 20s, died.
A client, who is in her 30s, was hospitalised in critical condition.
"An investigation into the cause of death has been launched," the Paris public prosecutor's office said.
Three people who were in contact with the victims and provided first aid also received treatment, the police source said.
The gym, where 150 people were present when the incident occurred, was evacuated shortly afterwards.
Nitrogen is a colourless, odourless gas that is commonly used in cryotherapy.
During a session in a walk-in chamber a person is exposed to temperatures below -100° Celsius for a recommended time of no more than three minutes.
Advocates say whole body cryotherapy is effective in reducing muscle soreness, stress, rheumatism and various skin conditions.
Star athletes and celebrities have used whole body cryotherapy as an alternative to ice packs and cold water baths.
But many experts warn that the treatment has not been proven to be medically sound and are urging further research to determine the short- and long-term effects.
Cryotherapy came under scrutiny in the United States in 2015 after a woman froze to death at a Las Vegas spa.
The 24-year-old was believed to have entered one of the spa's cold chambers after business hours to relieve some aches, and was discovered the next day by a co-worker.
