Infrared Sauna vs. Traditional Sauna: How Different Are They, Really?
The infrared sauna is marketed as a gentler, more convenient alternative to the traditional Finnish sauna — operating at a lower temperature, but supposedly delivering similar benefits. That's partly true, but the real story is more complex: both forms heat the body through completely different physical mechanisms, have very different depth and quality of evidence behind them, and one of the few areas where the infrared sauna has genuinely strong, randomized data concerns a narrow group of cardiac patients in Japan — not the general population looking for a biohacking edge.
KLdr Katarzyna LewandowskaSeptember 10, 202613 min read
In our knowledge-base entry on the sauna, we describe it mainly in its classic Finnish form — a dry sauna at 80-100°C (176-212°F), which is what the vast majority of the large cohort studies linking regular sauna use to lower cardiovascular risk and dementia risk are actually based on. The infrared sauna (IR for short) is often advertised today as its natural, gentler successor — it operates at a much lower air temperature (typically 45-65°C / 113-149°F), so intuitively it seems like "the same" intervention, just more comfortable.
Physically, though, these are two different principles of heating the body. The traditional Finnish sauna primarily heats the air in the cabin — heat reaches the body mainly through convection and conduction, meaning skin contact with hot air. The infrared sauna uses emitters that produce infrared radiation (usually in the near- and mid-infrared range), which largely bypasses the air and heats body tissues directly, penetrating somewhat deeper than mere surface skin heating. The subjective effect can feel similar — sweating and a sensation of heat — but the path heat takes to reach the body is different, which matters when comparing research findings between the two forms.
What this article does not repeat
If you're looking for general data on sauna use and blood pressure or sauna and testosterone, we cover those topics in detail in separate articles: sauna and blood pressure, and sauna and testosterone. Here we focus exclusively on what specifically distinguishes the infrared sauna from the traditional one — the mechanism, the strength of the evidence, and who each form might suit better.
The difference in cardiovascular load
The high temperature of a traditional Finnish sauna triggers a clear, fairly rapid cardiovascular response — heart rate can rise to as much as 100-150 beats per minute during a single, roughly ten-to-fifteen-minute session, comparable in intensity to moderate physical exertion. The infrared sauna, operating at a lower air temperature, generally produces a gentler hemodynamic response spread over more time — sessions tend to be longer (30-45 minutes versus 10-20 minutes in a traditional sauna), but the peak cardiac load is typically lower.
It's precisely this difference in intensity and the pace at which the load builds up that explains why the infrared sauna found its strongest clinical application in exactly this group — heart failure patients, a population that would often be unable to safely tolerate the rapid heart-rate rise and intense vasodilation typical of a traditional Finnish sauna.
Waon therapy — the strongest clinical data happens to concern the infrared sauna
Paradoxically, although it's the traditional Finnish sauna that has decades of large cohort studies behind it (chiefly the Finnish KIHD cohort), it's actually the infrared sauna that has one of the few genuinely randomized clinical trials with hard endpoints in this field — developed in Japan under the name Waon therapy by a team led by Prof. Chuwa Tei at Kagoshima University.
Waon Therapy for Managing Chronic Heart Failure — Results From a Multicenter Prospective Randomized WAON-CHF Study
Moderate evidence
Tei C, Imamura T, Kinugawa K et al. (WAON-CHF Study Investigators) · Circulation Journal · 2016
This multicenter, prospective, randomized study enrolled hospitalized patients with advanced heart failure (elevated BNP despite pharmacological treatment) at 19 Japanese centers. The intervention group received Waon therapy — a daily 15-minute exposure to a dry infrared sauna at 60°C, followed by 30 minutes lying under a blanket — for 10 days. The Waon therapy group showed significant improvements in BNP level, NYHA classification, 6-minute walk test distance, and cardio-thoracic ratio, with no serious adverse events related to the therapy.
Waon therapy was designed from the ground up for patients for whom a standard, hot Finnish sauna would be too great a hemodynamic burden — it's no coincidence that it's precisely the infrared sauna's lower temperature that made it possible to safely carry out a heat-based intervention in a group as clinically fragile as patients with advanced heart failure.
Repeated thermal therapy improves impaired vascular endothelial function in patients with coronary risk factors
Early-stage evidence
Imamura M, Biro S, Kihara T et al. · Journal of the American College of Cardiology · 2001
A study from the same center (Kagoshima) evaluated the effect of two weeks of daily thermal therapy (infrared sauna, 60°C, 15 minutes) on vascular endothelial function in people with cardiovascular risk factors. After two weeks, endothelial function (assessed by flow-mediated dilation, FMD) improved significantly, approaching values seen in healthy control subjects. Small sample, single research center, no strict placebo control group.
An important caveat: this is mostly one research school
Moderate evidence
The vast majority of randomized studies on infrared saunas in a cardiovascular context come from that same center in Kagoshima, Japan, and use the same patented Waon therapy protocol. That doesn't disqualify the results, but it does mean the evidence base is narrower and less geographically and methodologically diverse than the decades-long, multicenter observational base behind the traditional Finnish sauna — independent replication by other research teams at scale is missing.
Infrared sauna in chronic pain and rheumatic disease
Infrared sauna in patients with rheumatoid arthritis and ankylosing spondylitis
Early-stage evidence
Oosterveld FGJ, Rasker JJ, Floors M et al. · Clinical Rheumatology · 2009
A pilot study enrolled 17 patients with rheumatoid arthritis and 17 with ankylosing spondylitis, who underwent a series of eight infrared sauna sessions over four weeks. Pain and stiffness decreased in a clinically meaningful way immediately after a single session (pain by about 40%, stiffness by about 50% in RA patients), with some tendency for the effect to persist longer-term. The study was small, with no sham placebo control group, which limits how confident we can be in the conclusions — the improvement could have partly stemmed from the general relaxing effect of heat rather than from infrared radiation specifically.
This data is encouraging for people with chronic rheumatic conditions looking for non-pharmacological support in managing pain and stiffness, but its strength is limited by the lack of a sham-controlled comparison group — without one, it's hard to cleanly separate the specific effect of infrared radiation from the general effect of heat and relaxation alone, regardless of its source.
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What we DON'T know about infrared sauna — gaps in the evidence
No direct head-to-head studies of infrared vs. traditional sauna
Surprisingly, despite the popularity of both forms, there are practically no large, well-designed studies directly comparing infrared sauna with traditional Finnish sauna in the same participants within a single study. Most conclusions about the differences between them — including in this article — rest on comparing separate studies conducted in different populations, with different methods and different endpoints, rather than a direct head-to-head comparison. That's a significant limitation of this entire field of knowledge.
The infrared sauna also has no equivalent of the Finnish KIHD cohort — that is, a large, multi-year observational study tracking hard endpoints (mortality, heart attacks, strokes) in thousands of people using this form of sauna regularly over the years. Without such data, it's hard to say whether the favorable results of short-term Waon-therapy studies (10 days, 2 weeks) would translate into population-level benefits similar to those observed with years of traditional sauna use.
Be wary of marketing numbers
While researching this article, we came across many websites selling infrared saunas that cite specific, impressive-sounding statistics ("a study of 89 patients showed a 28% improvement in endothelial function," "a meta-analysis of 17 studies and 2,264 participants") without citing a verifiable source publication. We were unable to verify these specific figures in any indexed medical research database, so we deliberately don't repeat them here — and we'd encourage the same caution toward similar unsourced numbers found in sauna manufacturers' marketing materials.
Practical differences that matter when choosing
Feature
Traditional (Finnish) sauna
Infrared sauna
Air temperature
80-100°C (176-212°F)
45-65°C (113-149°F)
Heating mechanism
Convection — hot air
Infrared radiation — directly into tissue
Typical session length
10-20 minutes
30-45 minutes
Cardiovascular load
Higher, builds up faster
Lower, spread over more time
Evidence base
Large cohort studies (Finland, decades of observation)
Patients who can't tolerate high heat, including heart failure (Waon therapy)
Infrared sauna vs. traditional Finnish sauna — a practical comparison
Who each form may suit better
Cardiovascularly healthy people who want to base their practice on the most solid, long-standing evidence base — the traditional Finnish sauna has decidedly stronger population-level data
People who tolerate high temperature or a rapid heart-rate rise poorly — the infrared sauna, being gentler, can be easier to tolerate
Patients with heart failure or another significant cardiac condition — any form of sauna requires an unconditional consultation with the treating cardiologist here, regardless of type; Waon therapy was conducted in a hospital setting under medical supervision, not as an independent at-home practice
People with chronic joint pain from rheumatic disease — preliminary data suggests a possible benefit from infrared sauna, but this is an area that needs larger, controlled studies
Safety — the same precautions as with the traditional sauna
Who should exercise particular caution
Regardless of sauna type, people with unstable coronary artery disease, a recent heart attack, uncontrolled hypertension, pregnancy, or those taking diuretics or blood-pressure-lowering medication should consult a doctor about sauna use before starting a regular practice — the same contraindications we describe in our sauna entry apply to both forms of heat therapy. A lower air temperature in the infrared sauna doesn't automatically mean zero cardiovascular load — the longer session time can partly offset the lower temperature in terms of total heat load on the body.
Our editorial recommendation
The infrared sauna and the traditional Finnish sauna aren't simply the same intervention in two different packages — they differ in the mechanism of heating the body, the intensity of cardiovascular load, and, most importantly for an informed choice, the quality and scope of the evidence base behind each. The traditional sauna has decades of large, if observational, cohort studies with a clear signal of population-level benefit on its side. The infrared sauna has smaller but genuinely randomized clinical trials behind it, focused mainly on a narrow group of cardiac patients under one patented research protocol.
Neither of these evidence bases invalidates the other — they simply answer somewhat different research questions in different populations. The choice between them is therefore best based more on individual temperature tolerance, equipment availability, and, in the case of existing cardiac issues, a conversation with a doctor, rather than on the belief that one form is unambiguously scientifically "better" than the other.
A lower temperature doesn't automatically make the infrared sauna a weaker version of the traditional sauna — it makes it a different intervention, with a different, narrower, but in one area surprisingly strong evidence base.
Dr. Katarzyna Lewandowska, VitMode editorial team
Frequently asked questions
There are no direct comparative studies that would confirm this conclusively. The traditional sauna has decades of large cohort studies in a healthy population behind it, while the infrared sauna has solid, randomized data mainly in patients with heart failure and cardiovascular risk factors (Waon therapy) — these are different populations and different types of evidence that can't be directly compared.
It operates at a lower air temperature, which generally produces a gentler, more slowly building cardiovascular response — that's why it's sometimes used in cardiac patients unable to tolerate the high temperature of a traditional sauna. That doesn't mean it's free of contraindications, though — the same precautions regarding heart disease, pregnancy, and certain medications apply to both.
It's a therapeutic protocol developed in Japan by a team led by Prof. Chuwa Tei, using a dry infrared sauna at 60°C for 15 minutes, followed by 30 minutes lying under a blanket. It was studied mainly in hospitalized patients with advanced heart failure, under medical supervision — this is not the same thing as independently using a commercial infrared sauna at home.
No, there are practically no large, well-designed studies comparing both sauna forms head-to-head within a single study. Conclusions about their differences rest on comparing separate studies conducted in different populations with different methods, which is a significant limitation of this field of knowledge.
A small pilot study (Oosterveld et al., 2009) in patients with rheumatoid arthritis and ankylosing spondylitis showed a clear short-term reduction in pain and stiffness after infrared sauna sessions. The study had no sham-controlled group, though, so it's not possible to rule out that part of the effect came simply from the general effect of heat, regardless of the radiation source.
Partly yes, in terms of total heat load on the body — infrared sauna sessions typically last 30-45 minutes versus 10-20 minutes in a traditional sauna. That doesn't mean the lower air temperature is entirely irrelevant to safety, though — for people with cardiac contraindications, any form of heat therapy requires medical consultation regardless of session length.
It depends on the question. For long-term cardiovascular prevention in a healthy population, the traditional Finnish sauna has stronger data (large observational cohorts with decades of follow-up). For short-term therapy in heart failure patients, the infrared sauna, in the form of Waon therapy, actually has stronger data because it's randomized — this isn't a situation where one form is universally "better proven" than the other.
Specialist physician in cardiology, cardiovascular-prevention consultant
Katarzyna works as a cardiologist at a Warsaw teaching hospital and has spent years focused on cardiovascular prevention — trying, as she puts it, to convince people to change their habits before they end up on her ward, not after. She joined VitMode after a series of conversations with Anna at a lifestyle-medicine conference, where the two discovered they shared the same frustration: an internet full of contradictory claims about cholesterol, aspirin and heart supplements, with no clear signal of what's actually backed by research. She reviews content on cardiovascular health, lipid panels and pharmacological prevention, consistently distinguishing what helps a statistical population from what makes sense for a specific person. Off duty, she road-cycles — not for performance, but because, in her words, it's hard to write credibly about prevention without practicing it yourself.
