Sauna is an ancient technology.  Even modern variations (such as the electric sauna heater or the modern steam room) are just different methods of traditional hot-air bathing.

But what about the newcomer – INFRARED SAUNA?  What is it, and how does it work?  How does it compare to a traditional sauna?

Read below to find out.

Infrared sauna from – notice the steel grill (center), which is where you place your spine.

A Far Infrared sauna (FIRS) – notice the steel grills (center and low) – for your place your spine and legs.

What is an Infrared Sauna?

Infrared saunas are very different from traditional saunas.  They don’t use hot air – instead they heat your body FROM INSIDE, using microwave rays that penetrate 3-4cm under the skin.  In other words, traditional saunas heat the air (like a conventional oven), while infrared saunas heat objects themselves (like a microwave oven). 

NOTE: There are two varieties: FAR-infrared and NEAR-infrared saunas, with many advocates claiming that near-infrared is safer and superior.  See here and here for examples.  I won’t explore those difference today – a future post.  

Here’s a description from the best scientific article I could find on infrared saunas, published recently (July 2015) by a group from the University of Jyväskylä in Finland.  It’s about FAR infrared:

These saunas utilize 120-V infrared elements, similar to the infrared warmers on neonatal resuscitation beds, to radiate heat with a wavelength of around 10 μm. As infrared heat penetrates more deeply (approximately 3–4 cm into fat tissue and the neuromuscular system) than warmed air (only a few millimeters), users develop a more vigorous sweat at a lower temperature than they would in traditional saunas. Consequently, the cardiovascular demand imparted by thermoregulatory homeostasis (sweating, vasodilation, decreased afterload, increased heart rate, and increased cardiac output) is aerobically very light (Beever 2009).

Merro et al. (2015), ” Effects of far‑infrared sauna bathing on recovery from strength and endurance training sessions in men”,  SpringerPlus 4:321.  (Open access)

The article is especially interesting because it compares far-infrared sauna to traditional sauna bathing.  They find very little difference in the effects, except that traditional sauna caused a higher heart rate due to higher temperature + humidity.  Both are more beneficial than having no sauna.  Have a look at the paper.

But I have reservations about the article.  Although the science looks OK (not that I’m a scientist, and there are probably some issues with the research design), the study was “partly funded” by a sauna company (Harvia) … and the article gives infra-red sauna a really good wrap, almost like a sales pitch.  For example:

Some people find the aforementioned [traditional] practice uncomfortable. In contrast, far-infrared saunas (FIRS) heat to 40–60°C and provide a more comfortable and relaxing experience (Beever 2009 ) …

… In conclusion, deep penetration of infrared heat (approximately 3–4 cm into fat tissue and neuromuscular system) under mild temperature (35–50°C), and light humidity (25–35%) conditions during FIRS bathing are favorable for the neuromuscular system to recover from maximal endurance performance. In practice, FIRS bathing may be used among other recovery methods in athletes and also in other physically active people. FIRS bathing is a very light loading for the body compared to TRAD and provides a comfortable and relaxing experience. (Merro et al 2015)

This is disingenuous – it implies that FIRS is definitely more comfortable than traditional sauna – which is 100% a matter of preference.  But the article doesn’t treat it like a preference – it states it as fact.

I think they had the people at Harvia in mind – who also supplied the sauna for the test.  At least Harvia sells all types of saunas – traditional and infrared – so it’s not a blatant product placement … but I’m still uncomfortable with the above.   They could easily have been more circumspect, and they should have emphasized personal preference.  I can tell you that find a traditional sauna MUCH more comfortable and relaxing.  And I’m not alone.


What does an Infrared Sauna feel like?

I’ve only ever had one (1) infrared sauna – so I’m not an expert on them.  I’ll try more soon and report back, but the following is based on a single experience.


–  I’m sure there are different varieties.  The one I tried had heating pads that covered your spine when sitting on the bench, and another grill for your legs (like the picture at the top)  – these pads were the only parts that got hot.  The air itself isn’t very hot (only around 45Cº/115Fº).

–  For a few minutes I thought it wasn’t working on account of this very mild temperature.  But after 5 minutes, I was sweating profusely.  It was genuinely heating me from inside like a microwave oven, as the article above describes.

–  But without proper hot air, it really didn’t feel like a sauna to me.  It’s not as relaxing, not as intense.  Perhaps this feature will be attractive to certain people, but not to me.

Example of the coloured lights often found in infrared saunas – usually cycles through 3-5 colours. I REALLY don't like this. Pisses me off and kills the relaxation for me.

Example of the coloured lights (“colour therapy”) often found in infrared saunas – usually cycles through 3-5 colours. I REALLY don’t like this. Pisses me off and kills my relaxation.

–  I also didn’t like the coloured lights in the sauna – seems to be common with infrared saunas – usually called “colour therapy”.  Frankly, it really pisses me off.   I want a de-technologized sauna feel, not like I’m sitting in a laser show.  The best light was an off white that still wasn’t very relaxing.   Between this and the lack of hot air, the aesthetic experience was fairly poor.

–  You also have to sit in a specific position with your spine against the grill.  Very annoying for someone accustomed to traditional sauna, where sprawling on the bench is a real joy. And much less fun when sweating with other people.

–  HOWEVER – the biggest surprise is that when it was over and I was driving away in the car – I FELT LIKE I’D HAD A SAUNA.  Let me repeat: my body felt the same as if I’d had a sauna.  My cheeks were rosy – I felt fresh.  It was totally surprising, because nothing about the experience seemed like it would end this way.  But that’s what happened.   Again, this fits with the claims of the article above.  This is why I don’t mind infrared saunas being called saunas.


Infrared Sauna as Alternative Wonder Cure

Another thing you quickly learn about infrared sauna is that the market and demographic are also VERY different from traditional sauna.  They are more susceptible to being described as magic detoxification machines, often touted as far superior to “regular saunas”.  For example this place, near to me in Sydney (I haven’t visited) says:

A half hour session in our infrared sauna is a simple, enjoyable, non-toxic way to rid the body and skin of unwanted pollutants. In fact, de-toxification is 7 to 10 times greater than a regular sauna. This is because the body actually sweats more at Far infrared temperatures, which are 60 to 80% lower than conventional saunas. Your core temperature is raised slowly and a deep, purifying sweat is induced – all while you tune out. Listen to a CD or relax with a magazine in your private sauna.

Alkaline Spa and Clinic,
Potts Point, Sydney

Try searching “infrared sauna” and click on some links – most them have a similar flavour.  In fact, the article mentioned above (Morro et al. 2015) is one of the few things on FIRS that doesn’t have a pseudo-scientific feel to it.

Another regular claim is that infrared saunas can help to cure cancer (see here for a higher-quality version of the claim, with references) – compared to many of the more hackish/quackish sites (this one still has references at least, but the look and feel is pretty uninspiring).  The basic idea is that cancer cells don’t like heat, and that the penetrating heat of Infrared is even more deadly to cancer cells than the warm-air convection of traditional saunas.  Similar claims are made about its positive role in battling autoimmune disease.  The list would extend in a proper review.

NOTE: I am NOT saying these claims are false.  Instead, I’m saying they are regularly made in a way that makes inconclusive and scattered evidence look like established scientific fact.

So be careful about how people use the evidence they cite.  Infrared vendors typically seem more predatory on people’s anxieties and/or lack of knowledge about sauna – most of them display a distinct lack of knowledge themselves.  And many of the sites preaching the benefits of FIRS also sell the equipment …

… Caveat Shvitzor!


So my position is as follows:

  • While offering a dramatically different aesthetic and sensory experience, the end result of an infrared sauna seems to be similar to the effects of a traditional sauna.   My preference is 100% for the traditional type, because the heat of the room is what I find so relaxing.  The result may be similar, but I prefer the full-scale sensory experience by a mile.  I need to have more infrared saunas to confirm this, but I predict the opinion is unlikely to change.
  • Although advocates almost universally claim that infrared saunas have greater health benefits than traditional saunas – and although some scientific evidence can be construed to support this – the evidence is far from convincing.  Many more scientific studies are needed to document the effects of both – and even then, it depends what ailments you are trying to fix AND how much you value the smell and heat of traditional sauna (for me these are crucial parts of the de-stress routine).

At the end of the day, I absolutely prefer the intense sensory experience of traditional sauna to infrared sweating – the heat, the smell, the steam.  These trump any feature of infrared for me.  I appreciate the place of infrared saunas, and am glad if people use them.

But I do not appreciate the misleading nature of infrared sauna advertising, and this won’t be the last you hear about it.

Stay tuned for a fuller report.


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