Celebrities use the machine to lose weight. Chelsea Ake climbed in and couldn't get out.

Chelsea Ake managed a Las Vegas salon specialising in cryotherapy – a health and beauty treatment favoured by athletes, celebrities and the wealthy.

It involves customers standing in a capsule and being sprayed with freezing liquid nitrogen to temperatures below minus 150 degrees for just a few minutes.

But, 24-year-old Chelsea died last week after becoming trapped in a cryochamber for 10 hours when it failed to turn off.

Her friend, Shae-Lynn Bee told News3LV.com: “I do know that she was alone closing the shop up, and then did go into the machine and apparently did not turn off.”

“It’s very frustrating to know because you know there are no cameras in there,” Bee said.

“Basically, the only person that does know what happened is Chelsea.”

The local news station reports Ake may have suffocated while using the machine without any assistance in a tragic accident investigators have ruled stemmed from “operator error”.

“Frozen in solid Ice.” Family of cryotherapy manager says she was frozen to death https://t.co/JRXVyypRZT pic.twitter.com/1PDjoQoXUc

— NBC KSNV News 3 (@News3LV) October 26, 2015

But what on earth is this cryotherapy?

Cryotherapy has been used for years by athletes and is all the rage in the beauty world. With temperatures that can go as low as minus 170 degrees – far beyond the coldest natural temperature ever recorded on earth – the chambers were originally designed for medical purposes. It’s believed the extreme cold forces blood to the core and boosts oxygen levels in the body and white blood cells, reducing fatigue and soreness, increasing energy, stimulating the immune system and burning calories. The beauty benefits of submitting yourself to a few minutes of below freezing temperatures supposedly include an improved complexion and skin tone and a reduction in cellulite. It’s widely touted as an “anti-ageing” therapy. Medically they’re used to treat diseases involving inflammation, such as rheumatoid arthritis, and skin conditions like eczema, acne and psoriasis. In Australia, salons charge around $80 for a three-minute session.

@commonwealthlv saddened with loss of fellow friend and employee Chelsea Ake.@News3LV pic.twitter.com/tdBjx8uC8X — Antonio Castelan (@AntonioNews3LV) October 24, 2015

Isn’t this what people use to freeze themselves? Can’t they just bring her back to life?

While it is the same technology that people have chosen to use to freeze their bodies or heads shortly after death in the hopes that they can be resurrected at a time when a cure for their illness has been found, cryopreservation of people is not reversible with current technology.

Despite that, cryonic facilities such as Alcor Life Extension Foundation in Arizona charge up to $70,000 for brain preservation and $200,000 for whole body preservation.

(And apparently Walt Disney was cremated, not cryogenically frozen, as is widely believed.)