The short answer: yes. 85°C sits inside the 80–100°C band the Finnish Sauna Society recommends, which is the working range of Finnish domestic saunas. But there is a detail almost every article on this subject gets wrong, and it is worth knowing: the famous Finnish cohort studies never specified a temperature at all. They measured how often people used a sauna and for how long.
That distinction changes how you should read every temperature claim in this industry, including ours. If you want to know whether 85°C is enough, the honest route is to look at what the Finnish norm actually is, then look at what the research actually measured, and notice that those are two different questions.
Kiuas is the Finnish word for a sauna stove. The Kiuas Dry Sauna is a product made by Enhanced Human, an Australian recovery brand, named after the stove but built as a portable dry-heat sauna without stones or löyly. I have an obvious interest in the answer to this question, which is exactly why the section below sticks to what the papers say rather than what would suit us.
What the Finnish norm actually is
The Finnish Sauna Society recommends 80 to 100°C, with humidity sitting low between water pours, roughly 10 to 20 percent. That is the closest thing this category has to a standard, and it comes from the people whose practice the rest of the world copied.
Australian cabins with genuine stone stoves land inside it. Revel's traditional range states 85°C with a 110°C thermostat ceiling; Kiva's Reset cabins state up to 90°C and their Ritual outdoor cabins 90°C with the same ceiling (September 2026). A portable dry-heat unit at 85°C sits at the lower end of the same band.
Note where 85°C falls: comfortably inside the recommendation, at the cooler end. Not at the top. That is an honest description and it is also the useful one, because the top of the band is a real preference for a lot of experienced sauna users.
What the research actually measured
This is the part that surprised me when I went back to the source papers rather than to the articles quoting them.
According to PubMed, the headline study is Laukkanen and colleagues in JAMA Internal Medicine, 2015 ([DOI](https://doi.org/10.1001/jamainternmed.2014.8187)), following 2,315 middle-aged men from Eastern Finland with baseline examinations between 1984 and 1989 and a median follow-up of 20.7 years. Its exposure variable is described as the frequency and duration of sauna bathing assessed at baseline. Participants were grouped as using a sauna once a week (601 men), two to three times (1,513) or four to seven times (201). Compared with once weekly, the adjusted hazard ratio for sudden cardiac death at four to seven sessions was 0.37, with a 95% confidence interval of 0.18 to 0.75. That is the 63% figure everyone quotes.
The same paper also reports duration, which gets quoted far less often and is arguably more actionable. Against sessions of under 11 minutes, the adjusted hazard ratio for sudden cardiac death was 0.93 for 11 to 19 minutes and 0.48 for sessions longer than 19 minutes.
The dementia finding comes from the same cohort (Laukkanen and colleagues, Age and Ageing, 2017, [DOI](https://doi.org/10.1093/ageing/afw212)), with a hazard ratio of 0.34 for dementia at four to seven sessions weekly. The hypertension finding is a different and smaller sample from the same Finnish study: Zaccardi and colleagues followed 1,621 men without hypertension at baseline over a median 24.7 years and reported a fully adjusted hazard ratio of 0.53 (American Journal of Hypertension, 2017, [DOI](https://doi.org/10.1093/ajh/hpx102)).
Nowhere in those papers' reported exposure variables is a sauna temperature. Not a mean, not a range, not a minimum. The studies asked Finnish men how often they used a sauna and for how long, then followed them for two decades.
What that means, and what it does not
It does not mean temperature is irrelevant. These men were using Finnish saunas in Finland in the 1980s, which in practice means the 80 to 100°C band, and the researchers plainly did not consider a temperature question necessary because the practice was so standardised.
What it does mean is that anyone claiming that the research sets 80°C as a threshold is inventing a threshold those papers never set. The honest statement is narrower: these findings describe people practising Finnish sauna bathing at customary Finnish temperatures, so a sauna running inside that customary band is doing the thing that was studied. A 50°C session is outside it. Whether 85°C and 95°C differ in outcome is not a question these studies were built to answer.
All four findings are observational, which is the other constraint worth repeating. They describe associations in men who chose their own sauna habits, not demonstrated causes, and frequent users may differ from infrequent ones in ways statistical adjustment cannot fully separate.
What actually changes between 85°C and 100°C
Three things, none of which is "effectiveness" in any sense the evidence can speak to.
Tolerance and session length. Higher temperature means shorter comfortable sessions. Given the 2015 paper found longer sessions associated with lower risk, there is an argument, entirely speculative, that a temperature letting you sit for twenty minutes beats one that drives you out at eight. I would not build a purchase around that reasoning, but it is at least reasoning in the direction the data points.
Löyly. Above about 90°C with a stone stove you get the full traditional experience: ladle water on the rocks, humidity spikes for thirty seconds, evaporative cooling stops working and the room feels savage. That is not available at any temperature without stones, and it is the single biggest experiential difference between a cabin and a portable. Our piece on what a traditional Finnish sauna is covers the ritual in full.
Preference, which is not a lesser reason. Plenty of experienced sauna users genuinely prefer 95°C and find 85°C tame. If that is you, a stone-stove cabin is what you want and no portable will satisfy you. That is a real answer to the question in this title, and it is "no, for you".
Where beginners should start
Lower than 85°C, and by bench rather than by thermostat. A sauna is strongly stratified, so the lower bench in a cabin can be many degrees cooler than head height, and that is where beginners and children sit in Finland as a matter of course.
Five to ten minutes on a first session is plenty. Come out, cool down properly, and decide then whether to go back in. Build duration before temperature, and build both across weeks rather than inside a single session. The 2015 duration finding suggests time in the room is worth working up to; nothing suggests rushing it is.
Standard cautions apply and they are not boilerplate: a cardiovascular condition, pregnancy, or medication affecting blood pressure or thermoregulation means a conversation with your GP before a purchase decision. This is general information, not medical advice.
Where 85°C sits
- Finnish Sauna Society recommendation: 80–100°C
- Australian stone-stove cabins: 85–90°C working, 110°C ceiling
- Kiuas Dry Sauna: 85°C maximum, lower end of the traditional band
- Infrared cabins: 45–75°C where published, outside the band
- Steam rooms: about 40–46°C, outside the band
- What the cohort studies specified: frequency and duration, not temperature
Frequently asked questions
Is 85°C hot enough for a sauna?
Yes. It sits inside the 80 to 100°C band the Finnish Sauna Society recommends and matches the stated working temperature of several Australian stone-stove cabins. It is at the cooler end of that band, so experienced users who prefer 95°C will find it mild, and a cabin is the better choice for them.
What temperature were the Finnish sauna studies done at?
The papers do not say. According to PubMed, the 2015 JAMA Internal Medicine study and the 2017 Age and Ageing study define exposure by frequency and session duration, not temperature. Participants were using Finnish saunas in Finland, customarily 80 to 100°C, but no temperature figure appears in the reported exposure variables.
Is 100°C better than 85°C?
Not demonstrated. No study in this literature compares temperatures against outcomes, so any claim that hotter is better goes beyond the evidence. Higher temperatures shorten comfortable session length, and the 2015 paper associated longer sessions with lower risk, which arguably cuts the other way.
What sauna temperature should beginners start at?
Sit on a lower bench rather than lowering the thermostat, since saunas are strongly stratified and head height runs much hotter. Start with five to ten minutes, cool down properly afterwards, and build duration across several weeks before increasing temperature or session length.
Why do saunas feel hotter with humidity?
Because humidity stops sweat evaporating, and evaporation is your main cooling mechanism. Throwing water on hot stones raises humidity from around 15 percent to roughly 30 percent for half a minute. The air temperature barely moves, but your ability to shed heat drops sharply, so the same room feels far hotter.
How long should a sauna session be?
The 2015 JAMA Internal Medicine paper reported a hazard ratio of 0.48 for sudden cardiac death in sessions over 19 minutes compared with under 11 minutes, so longer sessions were associated with lower risk in that cohort. That is observational rather than a prescription. Build up gradually and stop when you have had enough.
An honest note on our own interest here
Our product tops out at 85°C, so an article concluding that 85°C is fine looks self-serving, and you should read it with that in mind. What I can offer instead of assurances is the checkable version: the Finnish Sauna Society's recommended band is public, the study DOIs are linked above, and the absence of a temperature variable in those papers is verifiable in an afternoon.
If you want the top of the band and löyly, buy a stone-stove cabin, and our Finnish-style sauna guide audits the Australian options against all five traditional criteria. If 85°C inside the band, from a wall socket, in a space that cannot take a cabin, is what you need, the specification is on the Kiuas Dry Sauna product page and the studies are listed on our science page.
Related reading