"How often do you use this?" I ask Cryospa Canberra owner David McPhan as casually as I can while the temperature on his cryosauna dips to below minus 100 degrees.

"About three times a week," he says, though he adds it's illegal to self-administer cryotherapy. Why? In 2015, a 24-year-old spa worker died of asphyxiation caused by low oxygen levels while in a whole-body cryotherapy machine.

Oh. With that in mind, I enter Canberra's first.

Lindsay Lohan, Kobe Bryant, Jennifer Aniston and Floyd Mayweather are among cryotherapy's devotees. It's meant to help with muscle inflammation, signs of ageing, skin tone, mood and energy levels. Participants may also burn up to 2000 kilojoules while shivering away their wrinkles and pain.

The science isn't proven, but most articles I read offer similar verdicts: athletes insist it helps with muscle recovery - as effectively and less painfully than an ice bath - while almost everyone else writes they've become addicted to the clear-headedness that follows bathing in liquid nitrogen.

"It started in Japan for arthritis and psoriasis," Mr McPhan explains. "It's not a miracle cure, but a general wellbeing business which is a bit more holistic."

I sign a waiver promising my blood pressure's OK, I'm not allergic to cold and my womb is uninhabited as Mr McPhan explains the process and his interest in opening Cryospa Canberra.

"I've always wanted a second business," he says. "[I've done] landscaping for 15 years. I stumbled across cryotherapy on TV one day and thought 'Why does Canberra have to be last to get things here'.

"I just thought it was a great idea. I think it's good for everyone and you can be in and out in 15 minutes."

I'm handed a pair of gloves and shown to an all-white room where I strip down to my underwear and cover myself in a robe. It feels very futuristic with white walls, a digital lock on the door and a television mounted on the wall. This is where people relax while waiting to be frozen.

Across the hall, in the cryotherapy room, Mr McPhan says I'll spend two minutes in the chamber at minus 140 degrees instead of the regular three minutes. I put on the provided socks and Ugg boots. With the gloves, I should be protected from frostbite and chilblains. He opens the door of the chamber and a thick mist spills out. I step inside.

It's cold, but I've felt colder back home on a crisp Tasmanian morning. It's not painful, either. Had I breathed properly, instead of worrying about dying of asphyxiation, I probably wouldn't have been so dizzy.

The only place I really feel it is in my legs, which feel a little as though they're being pricked with pins. Mr McPhan instructs me to do some squats. When I get dressed my clothes and shoes feel a little looser, just like on a cold day when everything contracts.

I do feel calmer and more switched on than usual for the rest of the day, but I don't exercise anywhere near enough to have any pains that need to be frozen into submission.

Verdict: Full disclosure: I panicked the entire time. It might have been fine had I not learnt of the potential for death. That said, the US woman spent 10 hours stuck inside the machine, not two minutes fully supervised. Would I do it again? Frankly, no. It's not for me. Plenty of other people can vouch for the experience though - if you're interested, give it a try.

Details: Cryospa Canberra is offering an opening special of $63 a session. Regular prices will be $90, while facials are $65 and spot treatment will be $55. Mr McPhan recommends people attend 10 sessions every two to three weeks to enjoy the full effects. Packages are also available. Visit Suite 5A, 3 Sydney Avenue, Barton, or cryospacanberra.com.au.