Infrared saunas have a celeb cult following, so we got in one to find out why

I've lived in Bangkok and sweated through many a hot yoga class. But an infrared sauna kicked my butt. If you've heard of infrared saunas, it could be because they're all the rage with celebrities these days. Jennifer Aniston reportedly has one installed one in her home, Gwyneth Paltrow extolled the benefits of the saunas on her Goop website, and Busy Philipps Instagrammed from one.

Why the obsession? Proponents claim benefits can range from fat burning and weight loss to "detoxification" and heart failure treatment. Experts say while some of these claims are true, backed up by scientific evidence, most are dubious. But if you're in good health and like a good sweat, there's no harm in trying one.

On a recent Sunday afternoon, I headed out in search of a good sweat – and perhaps the secret to Aniston's glowy skin – by trying infrared for myself.

Arriving at Vancouver's Halsa spa, owner Christian Mackenzie explained how I'd feel throughout the sauna session. Initially, I'd experience a gentle heat, "like a big, warm hug," he said. Then, just as I'd be wondering if it was going to work, I'd start to "sweat and sweat and sweat."

"Don't feel like you have to push through anything uncomfortable," he said, advising me to hop out and take a cool shower if I got too hot and to drink the lemon electrolyte water.

Still, I was nervous. I wondered if it would feel like my insides were cooking or like I was drowning in my own sweat.

But upon entering the private sauna room lined with cedar paneling and quiet, calming music filling the small space, I started to feel relaxed. I was surprised by how dry the air felt and how mild the temperature was – nothing like the uber-hot humid saunas that usually take my breath away.

I sat down and waited for the sweat to kick in.

I knew from my pre-sauna research that infrared saunas aren't actually as hot as traditional ones. Far-infrared saunas (FIRS) use infrared waves and radiant heat to heat the body – technology that's also used to keep newborn babies warm – whereas traditional saunas use burning wood or hot stones to heat the air, which then heats the body through convection. As a result, temperatures in a traditional sauna reach around 85C degrees, while infared saunas are typically around 60C degrees.

But I also knew lower temperatures wouldn't mean I'd sweat less. Infrared heat penetrates the body deeper than traditional sauna heat, meaning infrared-goers sweat more vigorously at a lower temperature than they would in traditional saunas, according to an article looking at far-infrared sauna health benefits by Dr. Richard Beever, a clinical assistant professor at the University of British Columbia, published in the journal Canadian Family Physician in 2009.

Ten minutes into my sauna session, I felt warm, as though I was sitting close to a burning fire. But I was still sweat-free.

It wasn't until the 15-minute mark when sweat droplets started forming. At the 20-minute mark, the sweat was falling from my skin. Thirty minutes in, I decided not to be a hero. I got out, showered and downed the lemon water. I returned and stayed in the sauna for the remaining 30 minutes, but I jumped out every ten minutes or so to cool off.

When my hour was up, I rinsed off and started to get dressed. I recommend giving yourself at least 10 minutes to cool down, especially if you're wearing jeans. Tight jeans plus warm, sticky skin do not mix, as I discovered.

Walking around immediately after, my face was rosy and I felt alert and calm, like I'd gone for a swim and then had a massage.

Though it would be hard to technically point to why.

The extent of the actual benefits of far-infrared saunas are unclear, with some claims unproven or under-researched, but there are some health benefits backed up by science, as Beever discovered when he wrote the report for Canadian Family Physician, which looked at previously published papers on far-infrared sauna benefits.

"Although the evidence is limited, it does suggest a number of benefits of FIRS use, including effects on systolic hypertension, New York Heart Association class and clinical symptoms of congestive heart failure, premature ventricular contractions, brain natriuretic peptide levels, vascular endothelial function, exercise tolerance, oxidative stress, chronic pain, and possibly weight loss and chronic fatigue," he wrote. "No adverse events were reported in any of the studies."

What they haven't proven to be is detoxification machines. "We do not have data that shows one can sweat out toxins in any meaningful way," said Dr. Catherine Forest, a clinical assistant professor at the Stanford University School of Medicine, in an interview with the New York Times in 2016. "But people feel better after they sweat and think they look better, and that's worth a lot."

Mackenzie just calls infrared saunas "super relaxing."

As for me, walking out into the fresh spring air my muscles feel relaxed and my skin felt glowy – perhaps not on an Aniston level, but close enough.

Katrina Clarke is a Vancouver- and Toronto-based journalist who writes about relationships, health, technology and social trends. Find her on Twitter at @KatrinaAClarke.