How Long Should You Stay in an Infrared Sauna?

Fifteen to thirty minutes covers almost all of the published research.

That's the honest ceiling on what science can tell you here. A 2018 systematic review pulled together 40 clinical sauna studies, and of the 25 that used infrared cabins, nearly every one ran sessions of 15 to 30 minutes at around 60°C, which is 140°F.¹ Researchers didn't pick that window because they tested longer sessions and found them worse. They picked it because it's long enough to raise core temperature and short enough that healthy volunteers will tolerate it repeatedly.

So if you're new to this, start at 10 to 15 minutes and work up toward 20 or 25. If you're using the sauna as a recovery tool after training, 20 minutes has the most direct evidence behind it. And if you're someone who could happily sit in there for 45 minutes, that's worth a slightly longer conversation, which we'll get to.

Why the Research Clusters at 15 to 30 Minutes

The 2018 review by Hussain and Cohen is still the most useful map of this territory. They screened the sauna literature from 2000 onward and found 40 clinical studies covering 3,855 participants, 25 of which used infrared cabins.¹ Every one of those infrared studies but two ran exposures at 60°C for 15 to 30 minutes.¹

That consistency is useful and limited at the same time. It means the reported effects, whatever you make of them, came from sessions in that window. It does not mean 31 minutes is dangerous or that 14 minutes does nothing.

The same review is candid about the quality problem. Only 13 of the 40 studies were randomized controlled trials, and most enrolled fewer than 40 people.¹ The authors close by saying that determining the optimal frequency and duration for specific health effects is still an open research question.¹ Anyone selling you a precise optimal number is going further than the evidence goes.

Infrared Runs Cooler, Which Changes the Math

Here's the part most sauna advice skips. Infrared and traditional dry heat are not the same stimulus, and duration guidance doesn't transfer cleanly between them.

Traditional Finnish saunas in the research run at 80°C to 90°C, or 176°F to 194°F.¹ Infrared cabins are considerably cooler. The studies in the review sat around 60°C, and the 2023 recovery trial used a cabin at 43°C, roughly 109°F.² Infrared panels warm your body more directly than they warm the air, so the air temperature reads low while you still sweat.

What that means practically: a cooler cabin is more comfortable, so people naturally stay longer. That's fine up to a point. But a longer session in cooler air isn't automatically equivalent to a shorter session in hotter air, and nobody has run the trial that would let us convert between the two. If you're tempted to sit for 45 minutes because it feels easy, understand that you've left the range anyone has studied.

What the Finnish Duration Data Actually Says

You'll see the 19-minute number quoted a lot, usually without its context, so it's worth being precise about it.

A 2015 study in JAMA Internal Medicine followed 2,315 middle-aged Finnish men for a median of nearly 21 years and looked at both how often and how long they used the sauna.³ Men whose sessions ran longer than 19 minutes had a 52% lower risk of sudden cardiac death compared with men whose sessions were under 11 minutes.³ Frequency showed a similar pattern, with the men going four to seven times a week faring best.³

Three caveats matter before you use that to justify longer sessions.

It's observational. Healthier men can tolerate longer, hotter sessions in the first place, and a study like this can't separate the sauna from the health that made the sauna comfortable. Epidemiologists made exactly that argument in JAMA Internal Medicine later that year, arguing the link may be noncausal and that reverse causation and confounding by fitness are hard to rule out.⁵

It was traditional Finnish sauna, not infrared. Different heat, different physiology, different exposure.

And it was 2,315 Finnish men aged 42 to 60. That's a specific population with a lifelong sauna habit.

None of that makes the finding worthless. A 2018 Mayo Clinic Proceedings review of the broader sauna evidence concluded that regular sauna bathing may support cardiovascular and other health outcomes, while noting that it should be discussed with your physician first.⁴ The signal is real enough to take seriously. It just isn't a dosing instruction for an infrared cabin in Illinois.

Session Length by What You're After

The recovery row has the cleanest evidence, so it's worth spelling out. Sixteen male basketball players did a hard resistance and plyometric workout, then either rested passively for 20 minutes or spent 20 minutes in an infrared sauna at 43°C.² Fourteen hours later, the sauna group's jump performance had dropped less, they rated their muscle soreness as less severe, and they perceived themselves as better recovered.² The researchers also checked overnight heart rate variability, a common marker of recovery, and found no sign that the sauna interfered with it.²

Sixteen athletes in a single session is a small study, and one trial doesn't settle anything. But if you want a number with a protocol attached to it, 20 minutes after you lift is the one that exists.

How to Build Up if You're New

Heat tolerance is trainable, and it adapts faster than most people expect. The approach that works is boring: add time gradually across visits rather than pushing hard in a single one.

A reasonable progression looks like 10 to 15 minutes for the first two or three sessions, then 20 minutes once that feels easy, then 25 or 30 if you want it. Most people land somewhere around 20 to 25 minutes and stay there, which happens to sit right in the middle of the research range.

Sitting on a lower bench, cracking the door for a minute, or stepping out and coming back all count as valid ways to manage a session. There's no prize for gutting it out.

Signs It's Time to Get Out

The timer is a guideline. Your body is the actual instruction.

End the session if you notice lightheadedness or dizziness, nausea, a headache starting, a racing or irregular heartbeat, confusion, or the specific and slightly alarming experience of stopping sweating while still feeling hot. That last one deserves attention rather than another five minutes.

Feeling pleasantly wrung out afterward is normal. Feeling wiped out for hours usually means the session ran too long, you went in underhydrated, or both. Adjust down next time.

Hydration and the Sweat Question

You lose fluid in a sauna, and how much varies enormously between people, cabins, and session lengths. Drink water before you go in and after you come out. If you're sweating heavily and going regularly, electrolytes are worth considering alongside plain water.

One thing to be clear about: the weight you drop during a session is water, and it comes back as soon as you rehydrate. Sauna sweat is not a weight loss mechanism, and it's not a detox mechanism either. Your liver and kidneys handle that work. Sauna use may support recovery, circulation, and stress regulation, and those are reasons enough without inventing extra ones.

Who Should Be Careful

Sauna bathing appears to be safe for most people, but the Mayo Clinic Proceedings review is explicit that it should be discussed with your physician before starting, particularly if you have a cardiovascular condition.⁴

Talk to a provider first if you're pregnant, have unstable angina or a recent cardiac event, have low or poorly controlled blood pressure, take medications affecting sweating or fluid balance such as diuretics, or have a condition that impairs your ability to sense heat. Alcohol and sauna are a genuinely bad combination and should never be paired.

The 2018 systematic review found a low rate of reported adverse effects across its 40 studies.¹

Sauna Sessions at Defiant in Lisle

Defiant runs a Radia IR 300 hybrid cabin at the Lisle clinic, serving Naperville, Downers Grove, Wheaton, and Chicago's western suburbs. The same cabin runs two ways: as an infrared session at around 130°F, or as a traditional Finnish-style dry heat session that climbs toward 200°F. Which one you choose changes how long you'll want to stay, and the difference is significant.

Booked sessions come in 30, 45, and 60 minutes at $45, $65, and $85. New clients can try a 30-minute session for $25.

If the research range is 15 to 30 minutes, why is the shortest booking 30? The booked slot covers your whole visit to the cabin. Getting settled, adjusting the heat, taking a break partway through, and cooling down all happen inside it. A 30-minute booking comfortably contains a 20-minute session at temperature with room on either side, which is the point.

The longer bookings make the most sense if you're running the cabin cooler, taking the session in rounds with breaks, or pairing heat with cold. That last option is contrast therapy, which alternates the sauna with the Everest CryoBuilt cryotherapy chamber and uses shorter heat rounds by design. Sauna sessions are also included as a Core Wellness credit in all three Defiant membership tiers.

If you're not sure where to start, tell the team what you're using it for. Twenty minutes after a lifting session and thirty minutes on a Sunday evening are different tools.

Frequently Asked Questions

Last updated August 31, 2026.