Steam is ancient. It curls through history, from Finnish löyly to the Roman laconicum, from Lakota sweat lodges to Turkish hammams. Across continents and centuries, humans have stepped into the heat not just to clean themselves, but to come undone a little, to reset, to heal. But in today’s wellness culture - buzzing with hashtags, infrared pods, and detox promises - the sauna has picked up some baggage.

Is it a miracle machine? A weight-loss trick? A cardiovascular threat? The internet has opinions. But behind the vapour is something simpler and deeper: a space for warmth, rest, and ritual. A space where myth often overshadows truth.

So here, we strip it back. Myth by myth. Steam by steam.

You must stay in the sauna for a fixed amount of time.

Truth: There is no universal timer—only your body.

Fifteen minutes. Twenty. Thirty. Somewhere along the way, we got the idea that sauna sessions came with fixed numbers - as though they were microwave instructions.

But in truth, sauna is less about precision and more about presence. Some people feel renewed after ten minutes; others luxuriate for thirty or more, dipping in and out between cold plunges or quiet contemplation.

The old wisdom still holds: leave while the sweat still feels good. While you want to be pushing somewhat into your zone of discomfort to access the resilience-building impact of sauna, make sure you step out before you're dizzy or drained. The feeling of discomfort - the 'I should get out or stop' feeling you get in sauna or exercise is triggered by an opioid called dynorphin. When that gets released, it has a downstream effect of upregulating the expression of beta endorphin receptors, so we are better able to deal with pain responses and get more of a euphoric feeling from beta-endorphin inducing exercises. Beta-endorphins also have a really interesting role to play in the bonding of social groups. Just remember: sauna is a conversation with your body—not a stopwatch.

Saunas detoxify the body through sweat.

Truth: Your liver and kidneys do the “detoxing”. Sweat plays a small supporting role.

The word “detox” has become overused and doesn’t have any agreed scientific meaning. And while it’s true that trace elements of heavy metals and chemicals can be found in sweat, they make up a fraction of the body’s processes.

Your liver, kidneys, and lymphatic system handle the heavy lifting. Sweating supports circulation. It can help you feel lighter, more clear, more “flushed.” But it doesn’t remove drugs, alcohol, or deep-seated toxins in the way some Instagram posts suggest. In effect, it's just water that is being pushed out of the blood and onto the surface of the skin to evaporate and cool the body as it does so.

Still—sauna isn’t a scam. It clears the mind, relieves tension, and resets the nervous system. That’s its own kind of cleansing.

The hotter, the better.

Truth: Heat is medicine—but medicine isn’t more effective in excess.

In traditional Finnish saunas, temperatures hover between 70°C and 100°C (158–212°F). Somewhere along the line, people began to treat this like a competition—chasing 110°C, 120°C, boasting of how long they lasted in “brutal” heat. The same thing happens with the cold plunge side of things, which is arguably even more dangerous.

But the goal isn’t punishment. It’s presence. When the heat gets too intense, the body stops responding with repair - it starts reacting with distress. Studies show that moderate, regular sauna use is a health-inducing adaptive stressor and improves circulation, reduces inflammation, and boosts cardiovascular function. But too much of that stress is just the usual damage-inflicting stress we should be avoiding at all costs. Not maximal, macho sweating. Just consistent, respectful heat.

The secret? Heat that feels challenging, not suffocating. Steam that opens you up - not knocks you down.

Saunas help build muscle.

Truth: Not directly—but they support the recovery that enables it.

You won’t get biceps from sitting in the heat. But you might train harder tomorrow because of it. That’s the link.

Sauna use has been shown to boost growth hormone temporarily. It enhances blood flow to tired tissues. Some studies even suggest sauna-induced heat shock proteins may reduce muscle breakdown and enhance repair.

So while it doesn’t replace resistance training or protein intake, it does make a compelling training ally—especially if paired with cold exposure and rest.

You lose weight in a sauna.

Truth: You lose water, not fat - and it comes back with your next glass.

A pound here, two pounds there - stepping off the sauna scale can feel triumphant. But the reality is this: the weight you lose is sweat. Water. Electrolytes. Nothing more.

Yes, sauna can support metabolic health. Some studies suggest improved insulin sensitivity or lowered cortisol, which can support weight balance over time. But the sauna is not a fat-burning furnace. It doesn’t torch calories like running a 5K. It won’t replace your strength training or walking practice.

A review paper from Tom Cullen at Coventry University concluded that sauna use can mimic all the effects of exercise (cardiovascular benefits, insulin resistance improvements, etc) except weight loss. However, if sauna use includes cold plunge, then that can have a weight loss effect as it promotes the development of metabolically active brown fat. People who have more brown fat on their bodies maintain a lower core temperature, and are more metabolically active even in the absence of movement/exercise - i.e. they're burning calories even when they're standing about not doing much!

It’s not a shortcut. But it is a beautiful companion to the long, slow road of well-being.

Saunas are dangerous for your heart.

Truth: Used properly, saunas support cardiovascular health.

This one lingers, especially among older adults or people with heart conditions. It’s true that saunas raise heart rate and blood flow. But this mimics the effect of mild to moderate exercise—like brisk walking.

In Finland, a nation of daily bathers, longitudinal studies have linked regular sauna use with reduced risk of sudden cardiac death, stroke, and hypertension. A 2018 study in BMC Medicine found that sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women. This study is promising but has limited applicability to the UK - you're considered a sauna nut if you go once a week, but that was the 'low frequency' in the Laukkanen studies! There isn't good data yet showing what happens when someone goes from 0 to once a week, which is something we're hoping to fix here in the UK!

But, as with all things, caution matters. If you have unstable heart disease, uncontrolled blood pressure, or a recent cardiac event, speak with your doctor first. Respect the limits—and the potential.

Infrared cabins are superior for muscle recovery.

Truth: They’re different—not necessarily better.

Infrared cabins have surged in popularity. Quieter. Cooler. Easier to install in urban flats or boutique gyms. Their claim? Deeper heat that penetrates tissue, increasing blood flow and aiding muscle repair.

And yes—some early studies show promise: lower inflammation markers, reduced delayed-onset muscle soreness (DOMS), maybe even faster lactate clearance. But traditional saunas, too, have centuries of evidence behind them. They stimulate heat shock proteins, improve circulation, and encourage deep rest—the very conditions muscles need to repair.

So rather than ranking one above the other, choose the one you’ll return to. That’s where the real magic lies.

Saunas can treat or cause cancer.

Truth: There is no scientific evidence that saunas cause or cure cancer.

Some fear the heat, worrying it might fuel tumour growth. Others claim saunas kill cancer cells. Both are misunderstandings.

While heat can influence cell behaviour in lab settings, real-world sauna use is not a cancer treatment—and has not been shown to trigger cancer either. What it can do is improve circulation, reduce stress, and support immune health—all of which may contribute to overall wellbeing during or after cancer treatment.

But it’s supportive care. Not a cure. Not a cause.

Saunas are only for cold weather.

Truth: They’re for any climate—because what they offer is internal.

Sure, there’s something poetic about steaming on a snowy lakeshore. But sweat bathing thrives everywhere: Mayan temazcals in tropical jungles, Siberian banyas in springtime thaw, mobile saunas on sunlit British beaches.

Sauna isn’t about external cold—it’s about internal contrast. The shift from hot to cool. From tension to release. From rush to rest.

So yes, you can sauna in summer. Yes, you can sweat beside the sea in July. The magic doesn’t melt—it transforms.

Going every now and then is enough.

Truth: For real impact, sauna should be a part of your regular routine.

It’s easy to treat the sauna like a spa indulgence - something you do on a ski holiday or once in a blue moon after a stressful week. And while that occasional session might feel lovely in the moment, the science tells a different story about lasting benefits.

The real physiological impact of sauna bathing—improvements in cardiovascular health, reduced inflammation, lower stress levels, and even reduced risk of dementia—comes from consistency, not occasion.

Think of it like this: going to the gym once a month doesn’t build muscle. Meditating once a season won’t meaningfully reduce anxiety. In the same way, occasional sauna sessions are nice—but they don’t move the needle. Weekly use, on the other hand, starts to shift internal patterns. Blood vessels become more elastic. The cardiovascular system learns how to adapt to heat stress. Hormonal and neurological systems regulate more effectively. Over time, your body remembers.

So if you want the benefits, make it a ritual. Make it part of how you care for yourself—consistently, quietly, week after week.

In the end: What do we keep?

Strip away the myths, and sauna becomes what it always was: A room. Some heat. Some silence. A place where the body is allowed to soften.

A place where healing isn’t forced, but invited.

So let go of the numbers. The timelines. Let go of “better,” “longer,” “hotter.” Sit. Breathe. Sweat. Feel. Step into the heat not for what it burns away—but for what it brings forward.

If you'd like to be at the heart of the sauna revolution, the British Sauna Society invites you to join us as a member. Connect with a network of sauna experts and enthusiasts and apply to join from as little as £10 per year.

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Sweat science: 10 sauna myths debunked