Sweating as a means of health restoration or maintenance is not a new concept. My horse girl-coded brain immediately goes to a haunting snippet from Laura Hillenbrand's acclaimed biography, Seabiscuit: An American Legend, in which the author describes how jockeys at a racetrack in 1920s Mexico would maintain their sport's strict weight requirements by sitting in a fermenting poop heap the size of a grandstand.

"It was prime sauna country," Hillenbrand writes. "Every day riders dug holes in the surface and burrowed in… It was almost too hot to take, but Mother Nature’s hotbox proved unbeatable for sweating off weight." Thankfully, technology has progressed to a point where we can hop in luxury devices like the MiHIGH Infrared Sauna Blanket instead of steaming shit mountains when we want to sweat it out.

Acquired in late 2022 by Gravity, the company that popularized weighted blankets, the MiHIGH is an at-home spinoff of the steadily growing market for infrared saunas, which heat the body directly using far-infrared heat (as opposed to traditional saunas, which have stoves that warm the air around you). It's been endorsed by a slew of professional athletes, from UFC fighters to rugby players, and it's sold out multiple times despite a $499 price tag.

The hook: Sit in the MiHIGH blanket several times per week for just 30 to 60 minutes to burn hundreds of calories, help your muscles recover after workouts, remove toxins, clear up your skin, improve your sleep, and destress. A MiHIGH ad that Facebook served me while I was researching it took things even further: "Just 45 minutes in an infrared sauna blanket… can change your life."

As to be expect with any product that promises dramatic results with minimal effort, we're dealing with some hyperbole, here — but I enjoyed my time with the MiHIGH nonetheless.

Unboxing the MiHIGH

The MiHIGH is basically an oversized sleeping bag lined with heating elements — well-made, but not especially glamorous. (I tested the original model with a Velcro enclosure; the V2 version is zippered.) It's constructed from heat-resistant artificial leather with a waterproof lining, and overall reminds me a lot of that lead apron you have to wear during X-rays at the dentist, with the same smooth, plasticky matte texture and heft. There's a little off-gassing right out of the box that makes it smell like an inflatable beach ball, which faded with time but never totally disappeared.

Setting up the MiHIGH is as easy as rolling it out onto a bed, couch, or carpet and plugging in its detachable digital controller, which has on/off, TEMP, TIME, and START buttons and a looong 12-foot power cord. There are nine temperature settings ranging from 95 to 167 degrees Fahrenheit and seven time options in five-minute increments from 30 to 60 minutes. It's simple, but maybe a little too simple: I wish the timer went down to five, 10, or 15 minutes so it's possible to extend an ongoing session, and for a better indicator that the blanket was on. (There's just a tiny flashing dot in the corner of the timer panel.)

The MiHIGH's controller is unimpressive, but that extra-long power cord is really nice. Credit: Haley Henschel / Mashable

Unlike some of Gravity's other offerings, this is not the type of blanket you drape over the back of a chair or put in a wicker basket when you're not using it. It weighs about 18 pounds and measures approximately six by seven feet when laid out, so it's kind of clunky to move around and store. It does come with a carrying case, but folding it down to size is something I have yet to fully master.

How it works

The heating elements within the MiHIGH emit far-infrared wavelengths — "far" referring to their position on the electromagnetic spectrum — and the resulting warmth is said to penetrate deeper than electric heat or hot air.

I worked my way up the MiHIGH's temperature range over the course of a few 30- to 45-minute sessions, giving it about five minutes to start heating up on level one or two each time before I shimmied in. I was skeptical at first, but its warmth really is cozier than any regular heating pad I've ever used. The mid-range settings between four and six were my favorite — very soothing, and not too overbearing. One advantage the MiHIGH has over regular saunas is that you can use it while watching TV or listening to a podcast, but if there were armholes in this thing that let me play my Nintendo Switch while simmering in it, like a flamin' hot Snuggie, you'd never hear from me again.

I thought I'd feel constricted inside the MiHIGH, as I get claustrophobic easily, but I had plenty of room to wiggle around in there. (I'm 5 foot 10, for reference.) I almost wish it covered me up slightly more: There's a semicircular cutout at the top end for your head so you can nestle down inside it, but your upper body still really doesn't get the bulk of the heat, which I'd hoped for as someone who carries a lot of tension in their neck and shoulders.

It took me about 15 to 20 minutes to start feeling like I was actually sweating at the MiHIGH's higher temperature settings (around seven and eight — nine was too much for me), though it's subtle when you're in there cooking. I didn't fully appreciate just how sweaty I got until I finished a session and realized that my clothes were drenched.

My MiHIGH review unit had a Velcro enclosure, but the latest version (V2, pictured here) is zippered. Credit: Gravity

…Did I mention that you wear a full outfit in the MiHIGH? I'm talking long-sleeved shirt, pants, socks, the works. The blanket's instruction manual offers it up as a suggestion, but the inside of it gets so hot to the touch at the middle to high settings that I'd say it's an absolute must. (I almost seared a sliver of my ankle when my sock drooped during one session.) It's not as uncomfortably weird as you'd think it would be, but it's still a little weird.

Once you've peeled yourself out of the MiHIGH, you're supposed to let it cool completely before wiping it down and folding it up. A fair warning, based on my own experience: There will be puddles.

All things considered, though, I was surprised to like stewing in the MiHIGH as much as I did. I wouldn't say it changed my life, but I'm convinced it helped with an old ankle injury that's been bugging me lately. (Hot showers tend to have the same effect, to be fair.) More broadly, it was just really great not to have to go anywhere or interact with anyone for a sauna experience, albeit a primitive one. I could just lay in bed in my cozy little infrared cocoon while catching up on Succession — which I did, many times.

I didn't use the MiHIGH long enough to find out if there was any truth to some of its bigger claims of calorie burn and detoxification, so I reached out to some experts for answers.

What science says about infrared sauna blankets

According to Dr. Mohammed Emam, assistant professor of Physical Medicine and Rehabilitation at Johns Hopkins Medicine and director at its Musculoskeletal Center, infrared radiation (i.e, the transfer of heat energy) has historically been used to relieve pain, ease muscle tensions, improve circulation, and promote relaxation.

The potential applications of infrared radiation-producing devices for weight loss, improved metabolism, and detoxification have been the subject of recent studies, Dr. Emam said, and some have found evidence of a biological response to infrared radiation. However, "more research is needed to validate these health claims and evaluate efficacy and safety profile of using these infrared devices such as the infrared sauna blanket," he wrote in an email. (It should be noted that none of the MiHIGH's purported benefits have been evaluated by the FDA.)

Dr. Cheree Padilla is a family physician and assistant professor at the University of Florida who specializes in sports medicine; she owns a portable personal infrared sauna. Dr. Padilla believes there is some validity to claims of infrared sauna blankets contributing to weight loss — provided they're used consistently and treated as a supplement to healthy eating, sleeping, and exercise habits.

In terms of tangible results, "I think people immediately will get the benefit of feeling relaxed and sleeping a little bit better," she told me, similar to the effects of sweating during a workout.

Both Drs. Emam and Padilla flagged some potential risks of infrared sauna blanket use.

"The depth of infrared penetration into the skin depends on the specific wavelength, intensity, and duration of exposure," Dr. Emam wrote. "However, it's important to note that excessive exposure to intense or prolonged infrared radiation can have adverse effects on the skin, such as thermal injury or burns." People with chronic medical conditions or inflammatory conditions, pregnant people, and children should steer clear, he added.

Dr. Padilla stressed the importance of staying hydrated during infrared sauna use and starting with short sessions at low temperatures to build up your heat tolerance. She also recommended choosing an infrared sauna blanket with no or low levels of electromagnetic fields. (The MiHIGH is a low-EMF model, for what it's worth.) While they don't cause cancer, EMFs can counteract positives of infrared heat such as reduced stress and inflammation, Padilla said.

Final thoughts: Should you cancel your gym or spa membership?

The MiHIGH comes with a carrying case, but good luck folding it down to size. Credit: Haley Henschel / Mashable

As much as I like being swaddled by its polyurethane embrace, the MiHIGH is certainly not a necessity. But if you're someone who's sick of spending time in your gym or spa's infrared sauna, it makes a convenient alternative — and possibly a more affordable one.

To put things in perspective, the cost of à la carte sauna sessions at spas near me range from $50 for a 30-minute session to $65 for a 45-minute session. You'd have to use the $500 MiHIGH 10 times max to get your money's worth. (Granted, it doesn't come with amenities like fancy bathrobes and free juice, but you also don't have to share it with strangers with questionable hygiene habits.)

Five hundred dollars isn't a small amount of money to spend on a wellness device, but it still puts the MiHIGH on the cheaper end of the spectrum among popular, well-reviewed infrared sauna blankets: The HigherDOSE Infrared Sauna Blanket, the Heat Healer Infrared Sauna Blanket, and the HydraGun HeatPod Sauna Blanket retail for $699, $598, and $499, respectively. What's more, the MiHIGH went on sale for $399 while I was writing this review.

Could be crappier, I suppose.