Finnish sauna heat exposure induces stronger immune cell than cytokine responses

4 hours ago (tandfonline.com)

In Finland we have old saying: "If liquor, tar and sauna won’t help, an illness is fatal"

All of these studies are always performed by Finns (or SE / DK / NO + maybe Russia).

I'd love to see this (and other sauna studies) replicated by someone somewhere to the south or hotter climates in general (southern Europe, Africa, hotter parts of Asia and the Americas).

  • And also replicated with participants not used to high temperatures inside a typical Finnish sauna. As the study said such people are very difficult to find in Finland. But I wonder if a person who has never been to a real sauna would tolerate this study protocol (2*15 min at 73° Celsius) without any training.

    Sauna and hot climates may sound counterintuitive, but it has been tested by most Finns that when you come out of a hot sauna any outside temperature feels cool.

  • There’s a saying in Finland that foreign "saunas" are not true saunas at all, but rather just "untypically warm rooms".

    The experiments where at 73°C which is a lot hotter than most gym/hotel/spa saunas I’ve been in outside Finland

    • Also while 73°C is a proper sauna, there are plenty of hotter ones. 90°C is closer to what I'm used to at my apartment building's common sauna. I do take two breaks when I'm there for 30 mims though.

>mitigate the adverse effects of low socioeconomic status

Makes me wonder how much of it is Sauna, vs just the luxury of having the time to go do nothing for ~30 minutes.

  • I just cannot fathom comments like this. I’m preeetty sure that the vast majority of people spend half an hour a day doing nothing, in front of a screen of some type. How many people do you think there are there who don’t have thirty minutes of leisure time once per week?!

    • There's a world of a difference between being able to carve out 30 actually uninterrupted minutes (and realistically more; most people don't have a sauna in their home, so they'd need to spend some time getting there and back) and being able to zone out and stare at a screen for 30 minutes in bed or on public transit.

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    • Are you even living if you're not spending every single minute breathing and shitting your work and/or kids?

    • You "cannot fathom" the privilege your have or life experience you lack to believe this unconditionally.

  • Less doomscrolling, less bing watching of dumb Netflix series. Sensible working hours. And a society that doesn’t demand constant reachability when being off work.

    It is not a luxury. It is living with common sense.

  • As an American: I soak in a hot tub for 30 minutes or more, at fairly high heat. At least a few times a week.

    Sometimes posting on Hackernews.

    It’s one of the high points of my day (the soak, not the posting).

    This “I wonder” just screams lazy thinking.

  • I nearly made a screen time comment but you are right, its facility availability and travel time issue more than anything

    • Finland has saunas everywhere, having a sauna at home isn't even expensive average people have that, its just a cultural thing its like having a toilet at home it isn't something normal people can't afford.

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  • People with high socioeconomic status work much more and have less free time. It’s absurd to claim otherwise.

    EDIT: please before being outraged at my comment have a look at actual evidence, e.g. Time and income poverty by Tania Burchardt; bottom decile compared with top decile has 12 hours more free time a week!

    • > People with high socioeconomic status work much more and have less free time

      I think you are misrepresenting (or perhaps, misunderstanding) the conclusion of these studies. The increased "free time" is most entirely due to high unemployment at the lower end of income.

      If you control for unemployment and under-employment, the graphs pretty much flatten out (as you can observe in the later graphs of the publication you linked below)

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    • Citation needed.

      Edit: it’s absolutely not true universally and it’s ridiculous to suggest it is. Comparing averages will be very tricky as well.

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> A total of 51 adults (...) were exposed to a 30-minute session of acute FSB at a temperature of + 73°C

Woah, that seems like a lot for me. I can usually stand maybe 60ºC for like 10 maybe 15 min. I don't think I'd be able to stand 30 min under 73ºC.

  • Humidity is the key, Finnish style sauna is low humidity+ high temperature (85-115C is OK i think), while Russian banya-style is low temperature (60-80C with high humidity). Both of them produce about the same load on a human

    • That's interesting. I don't have much the habit of doing sauna, as you can likely tell, so I might have tried only high humidity saunas. I'll give it a try one day with low humidity if I find one.

  • 73°C is a bit unusual cold for a Finnish sauna. Wikipedia says:

    > The temperature in Finnish saunas is 80 to 110 °C (176 to 230 °F), usually 80–90 °C (176–194 °F)

    And with that temperature, I think 10–15 minutes are pretty standard.

    • 73°C isn't unusual. I checked out what's source for the Wikipedia article that says it's 80 to 110°C. Oddly it's a Chicago Tribune article from 1970. I don't think I ever visited a 110°C sauna.

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  • I was in a 110C sauna for 20 minutes today. Plus 15 minutes in a 70C one (hybrid infrared sauna). Max is 30 minutes at once at 70C. It does take some getting used to.

  • The sauna at my gym is regularly over 180F and I do 30 minute sessions. It is a dry sauna however, no steam.

Anecdotal evidence. But since I started doing sauna regularly (once a week) I started to get sick less. I’m talking colds or flues. And the ones I did catch were much milder. Even with sick family members around I’m not catching it as often.

I’m not sure if I want a response of cytokine storms. MCAS is what comes to mind.

I’ve always wondered if it raises internal body temperature? Is it basically an induced fever?

  • It does indeed increase internal temperature. Perhaps an artificial fever is part of it but I believe the science currently around heat shock proteins.

Does a long hot bath do the same?

  • It might not do the exact same, but it will have some effect. A lot of the benefit comes from the raised heart rate and opening of the blood vessels that the sauna produces, and I can expect that a warm bath would also have a similar effect. I think both are also known to reduce stress, which can help to lower blood pressure.

  • Yes, if by hot bath you mean submerging yourself to neck level in 40ºC or above water for 20-30 minutes. There's no reason to believe any "heat therapy" modality is superior to another as long as you suffer equal heat stress.

    For the record, if you're not acclimated, intense heat exposure is a lot more agonising than 30 minutes of exercise for less benefit. If you haven't experienced a properly tuned sauna in your life you are in for a ride. What's being studied in the literature is nothing like your standard hotel experience.

    • How are you suffering equal heat stress from being submerged in moderately warm water and breathing very hot air? I could imagine quite different effects on airways and skin, for example. "Exactly the same effect" seems like the unexpected outcome here.

      > intense heat exposure is a lot more agonising than 30 minutes of exercise for less benefit

      Having to do absolutely nothing other than not leaving is quite different from pushing through a physical activity that can also easily be causing all kinds of discomfort.

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