We do not offer this. There is no sauna at Restorative Wellness Center, traditional or infrared, and no heat therapy service of any kind. This page is education, written because patients ask me about it. I am a dentist. My clinical work is jaw joints, facial pain and breathing during sleep, and sauna sits outside that. Nothing here is medical advice and nothing here is a protocol for you.

The short answer

There is a famous sauna study. It is large, it is careful, and it is almost certainly not about the sauna you are thinking of buying.

The evidence people cite comes from traditional Finnish dry sauna, studied in Finland, in men, across twenty years. The cabinet most Americans actually buy is an infrared cabin, which is a different exposure at a different temperature. The study authors said so themselves, in the paper, in a sentence almost nobody quotes.

I own an infrared cabin. It is the one with less evidence behind it. That seems worth saying out loud rather than leaving at the bottom of the page.

What the Finnish study found

A prospective cohort followed 2,315 middle-aged Finnish men for a median of 20.7 years. Compared with men who used a sauna once a week, men who used one four to seven times a week had lower adjusted risk of sudden cardiac death, of fatal coronary heart disease, of fatal cardiovascular disease, and of death from any cause.

The numbers are striking. For sudden cardiac death the adjusted hazard ratio was 0.37, with a confidence interval between 0.18 and 0.75. For death from any cause it was 0.60.

Now the parts that rarely get quoted

Two hundred and one men. That is the size of the four-to-seven-times-a-week group, out of 2,315 in the cohort. The headline rests on them.

The middle group missed significance. Men using a sauna two or three times a week had a hazard ratio of 0.78 for sudden cardiac death, with an interval running between 0.57 and 1.07. That interval crosses one. It is not the clean dose response it gets described as.

Nobody was assigned to a sauna. This is an observational cohort, so it cannot establish cause. The authors write that residual confounding remains, and that underlying diagnosed or undiagnosed disease may affect sauna habits. In plainer words: a man too unwell to sit in a hot room seven times a week is also a man more likely to die. The sauna may be a marker of health rather than a cause of it.

Men only, one country, one culture. The authors say similar studies should be done in women, and in people not accustomed to regular sauna use. Exposure was measured once, by questionnaire, at the start, and the twenty years that followed were not observed.

The same journal published a challenge. A letter argued the link may be noncausal, pointing out that the estimated risk reduction is as large as or larger than that of proven drug treatments. When a pleasant leisure habit appears to outperform pharmacology, the first place to look is the study design.

Why that evidence stops at the sauna door

Here is the sentence from the paper that the marketing never carries. The authors write that their results, from hot Finnish sauna bathing at a mean of 79 degrees Celsius, cannot be directly applied to steam rooms, hot tubs and some other types of sauna, which operate at lower temperatures and do not allow pouring water on the rocks.

Read the two conditions they give. A lower operating temperature, and no water on the rocks.

An infrared cabin fails both. It runs far cooler than a Finnish sauna, and it has no rocks and no water in it at all. The caveat the authors wrote for steam rooms applies to infrared with more force, not less.

This is the most common error in the category, and it is usually made by somebody selling a cabin.

What the infrared evidence actually is

Randomized evidence for infrared heat does exist, and it is not what the marketing implies.

A 2018 systematic review and meta-analysis of infrared sauna pooled seven studies and 491 patients, every one of them with heart failure. The trials studied Waon therapy, a defined medical protocol delivered in a clinical setting at 60 degrees Celsius for fifteen minutes, followed by a supervised thirty minute rest in a warm environment, five times a week.

Every one of them had a weakened heart muscle. The review found improvements in ejection fraction, in B-type natriuretic peptide and in cardiothoracic ratio, and the authors rated their own certainty from moderate down to insufficient.

So the honest summary is a small body of trials, in sick patients, using a supervised clinical protocol with a rest period built into it. Whether any of that reaches a healthy person sitting in a backyard cabin is not a question those trials were built to answer.

What I own, and what I think about it

This section is personal experience. It is not evidence and it is not a recommendation, and I have kept it separate from everything above on purpose.

I have an infrared cabin at home and I use it. What I get from it is mental more than physical: nervous system regulation, resilience, the value of having deliberately done an uncomfortable thing. That is my reasoning and my experience, and I am handing it to you labelled as exactly that.

What I am not going to do is tell you it lowers inflammation or speeds healing. I have believed that, and I still suspect some of it is true. Suspecting something and having evidence for it are different things, and the whole point of this library is keeping them apart.

Who should ask a doctor first

Heat is a cardiovascular load. Vessels dilate, heart rate rises, and blood pressure can fall sharply on standing up afterwards.

Ask your own doctor before starting if any of these apply: any heart condition, unstable angina, a recent heart attack, any history of arrhythmia, low or unstable blood pressure, pregnancy, or any condition or medication that affects how you regulate temperature or stay hydrated.

Two practical ones whatever your history. Do not combine heat with alcohol. The Finnish paper notes that alcohol together with sauna bathing has been a major contributing factor in the small number of sudden deaths that occurred around sauna use. And do not use one alone if you have any reason to think you might faint.

I want to be plain about the limits of that list. I am not a cardiologist and I am not your physician. This is the part of the subject where you should want someone with the right training, and that is not me.

Common questions

Is an infrared cabin as good as a Finnish sauna?

Nobody knows, because the comparison has not been done properly. They are different exposures, studied in different people, for different outcomes. Anyone who tells you the evidence for one is the evidence for the other has not read either.

Does a sauna detoxify you?

That is not something I can support and it is not what any of the studies above measured. It is the claim I would be most careful about, because it is the one used to sell cabins and the one with the least behind it.

How hot, and how long?

In the Finnish cohort the average was 78.9 degrees Celsius for about fourteen minutes. The Waon protocol was 60 degrees for fifteen minutes with a thirty minute rest afterwards. Those are descriptions of what was studied. Neither is a prescription for you, and there is no established consumer dose here.

Will it help my jaw pain?

Nothing in this literature speaks to jaw pain, and I would not suggest a sauna for it. If your jaw or face hurts, the useful step is finding out why.

Where to go next

The same pattern shows up in cold exposure, where the claims also run ahead of the trials. How we grade evidence is set out in our editorial standards, and the rest of the library is at health optimization.