I have been feeling the heat recently. That claustrophobic quality a summer can have, when the windows are open, yet there’s no escape. Desperate for a means of cooling down, I’ve been obsessed with the idea of whole-body cryotherapy (£95 for three minutes, 111cryo.com): getting into a chamber that has been plunged into sub-zero temperatures. Friends were sceptical. “Your organs are going to slow down,” warned Selina, a nurse. This was not welcome news. Slowing down is, after all, connected to stopping. I told Selina I had booked a session with 111Cryo at Harvey Nichols, which reassured her. “I thought you’d met some guy with a lock-up in Acton who wanted to show you his chest freezer,” she said.

The frozen chest I am most worried about is my own, as I strip down to my pants on the fourth floor of the department store, next to ladies’ fashion. To protect my extremities, my nakedness has been complicated by North Face puffer booties, shorts, ski gloves and a headband for the ears, plus a thin face mask to keep my breath warm. I feel cool. Boxing cool.

“In the blue corner, weighing 10 stone and change, Rhik ‘Dignity’ Samadder!” I announce in my head, shadow sparring while an employee checks the chamber temperature. I stop jogging when I see what it says: -85C. What? I haven’t thought this through. That is too cold. The nice man opens the door and vapour pours out. Shaking like the disputed champion of the world, fish finger division, I step inside.

Cryotherapy targeted at specific points on the body has been approved to remove warts and relieve rheumatoid arthritis. The whole-body version is a different matter. It is promoted as a panacea, treating everything from eczema to anxiety to weight loss and migraines. The most plausible claims hold that freezing can reduce inflammation and promote muscle recovery – which is why it is so popular with top athletes – but this is unverified. The process has been updated, though: the traditional procedure involved lying in a tunnel into which liquid nitrogen was pumped. Nonetheless the whole thing still carries a deranged supervillain, Mr Freeze-style nuttiness to it.

The chamber is the size of a large shower, with smooth walls and a grated ceiling. A fan above circulates freezing air. There is what looks like snow on the ground and swirling around me, exactly like a snow globe. Electronic music plays. It is as cold as the lowest temperatures recorded in Antarctica, and I am wearing booties. Is this how I die? In corporate shorts?

Due to a powerful dehumidifier, the air is a dry cold similar to that found in countries such as Russia. Apparently, dry cold stays near the surface of the skin and does not penetrate the organs. Weirdly, it’s bracing, but ... nice? I have remembered to accumulate a thick layer of body fat over decades, a decision that is coming into its own. My insides remain warm while I’m in the supermarket chiller cabinet, an honorary chicken kiev.

Ice to see you. Photograph: Linda Nylind/The Guardian

After three minutes, my time is up. I feel very awake, my limbs smooth and pleasantly numbed. My pores have closed, giving me flawless skin. I’m told that, because the body has experienced shock, I’ll burn 500 calories over the next few hours. (It is hard to judge if this is the case, as I eat a sharing bag of tortillas and a Lion bar within the same timespan.) My mosquito bites have stopped itching, though. An achilles tendon that had been sore for weeks is no longer bothering me. Yet any impact of whole body cryotherapy is almost certainly temporary. By the evening, my heel aches again. I do sleep well.

The supposed benefits for lymph drainage and skin conditions won’t make themselves felt in a single session; at £95 for 180 seconds; to stay the course requires a fat wallet. If you’re as loaded as a comic-book villain with pain-management issues, consider casting your cold, dead eyes towards cryotherapy. Those who can’t pay, pray for a break in the weather. Or not: the day after my session, it started raining and was cold again. A wet cold, the kind I had forgotten about. Enough to make me cryo myself to sleep.

Wellness or Helsinki?

The advantages for sleep could be true. A Finnish friend told me that, in her country, babies are wrapped up and taken outside in the snow, to encourage them to nap. I have never been told a single fact about Finland that doesn’t make it sound like Sparta.

Wellness or hellness?

The pounds just melt away. 2/5