Infrared Sauna vs. Wood-Fire Sauna: What the Science Actually Says

A science-backed comparison of two of the world's most popular heat therapies

Saunas have been a cornerstone of human wellness for thousands of years. From ancient Finnish sweat lodges to sleek modern infrared cabins, the practice of exposing the body to intense heat is enjoying a renaissance — and for good reason. A growing body of peer-reviewed research confirms that regular sauna use can support cardiovascular health, mental well-being, pain relief, and even longevity.

But not all saunas work the same way. If you've ever visited us here at Fyre Sauna, you've seen both options side by side: our authentic wood-fire Finnish sauna and our infrared sauna, each offering a distinct heat therapy experience. One of the questions we hear most from guests is: which one is better for your health?

The answer, as with most things in health science, is nuanced. This post breaks down the key differences, with the research to back it up.

How They Work: The Fundamental Difference

Before comparing health outcomes, it helps to understand the mechanics.

Wood-fire (Finnish) saunas heat the air around you. A wood-burning or electric stove heats a pile of rocks to extremely high temperatures, and the room fills with dry, hot air — typically between 80°C and 100°C (176°F–212°F), with relative humidity kept low at 10–20%. Users can briefly increase humidity by pouring water over the stones, creating a burst of steam known as löyly. A typical session involves multiple 10–20 minute rounds of heat exposure interspersed with cooling periods.¹

Infrared saunas use infrared light emitters — near, mid, or far-infrared wavelengths — that penetrate the skin and heat the body directly, rather than warming the surrounding air. This allows infrared saunas to operate at much lower ambient temperatures, typically between 43°C and 60°C (110°F–140°F), while still raising the body's core temperature and inducing a significant sweat response. As Dr. Rachele Pojednic, Chief Science Officer at Restore, explains, infrared saunas offer benefits "not only from getting hot, but potentially from direct exposure to therapeutic wavelengths of light."²

This fundamental difference in heat delivery has real downstream effects on the body — and on who can tolerate each type. At Fyre Sauna, we've intentionally kept one of each on the property so guests can experience both and discover what works best for them.

Cardiovascular Health: Traditional Sauna Has the Strongest Evidence

When it comes to heart health, the traditional Finnish sauna has a commanding lead in the scientific literature — not because infrared saunas don't work, but because the long-term epidemiological data simply doesn't exist for infrared yet.

The landmark research comes from Dr. Jari Laukkanen and colleagues at the University of Eastern Finland. In a landmark 2015 study published in JAMA Internal Medicine, they followed 2,315 Finnish men for a median of 20.7 years and found that sauna bathing frequency had a dose-dependent inverse relationship with cardiovascular mortality. Compared to men who used the sauna just once a week, those who bathed 4–7 times per week had a 63% lower risk of sudden cardiac death, a 48% lower risk of fatal coronary heart disease, and a 50% lower risk of fatal cardiovascular disease.³

A follow-up cohort study published in BMC Medicine in 2018 extended these findings to women as well, confirming that regular sauna use was independently associated with reduced cardiovascular mortality across sexes.⁴

How does it work? A comprehensive 2018 review published in Mayo Clinic Proceedings outlined the likely mechanisms: sauna bathing mimics moderate-intensity exercise by raising heart rate, improving arterial compliance, reducing blood pressure, and favorably modulating inflammatory markers like C-reactive protein. The authors also noted that frequent sauna users — those bathing 4–7 times per week — had a 66% reduced risk of dementia and a 65% reduced risk of Alzheimer's disease compared to once-weekly users.⁵

Infrared saunas are not without cardiovascular benefits. A 2009 review in the Canadian Family Physician found that far-infrared sauna use was associated with improved outcomes in patients with heart failure, hypertension, and peripheral artery disease.⁶ A 2022 randomized controlled trial published in the American Journal of Physiology found that regular sauna bathing combined with exercise produced significant cardiovascular improvements, including reduced arterial stiffness.⁷

Bottom line: Traditional Finnish saunas have decades of large-scale human evidence connecting them to major reductions in cardiovascular mortality. Infrared saunas show promising cardiovascular effects, but the evidence base is smaller and shorter in duration.

Heat Penetration and Comfort: A Key Physiological Difference

One of the most significant practical distinctions between the two sauna types is thermal comfort and tolerability.

Because infrared saunas operate at lower ambient temperatures, many people — particularly those with respiratory conditions, heat sensitivity, or cardiovascular vulnerabilities — find them far more accessible. A systematic review published in Evidence-Based Complementary and Alternative Medicine (2018) found that infrared saunas were used in the majority (25 out of 40) of clinical sauna studies reviewed, and that their lower operating temperatures may make them suitable for populations who cannot tolerate the intense heat of a traditional Finnish sauna.¹

Infrared radiation penetrates the skin more deeply than convective heat, potentially heating soft tissues and muscle more directly. This has led to particular interest in infrared saunas for musculoskeletal pain relief and post-exercise recovery. A 2023 study in Biology of Sport found that a post-exercise infrared sauna session significantly improved recovery of neuromuscular performance and reduced muscle soreness after resistance training.⁸

Traditional saunas, by contrast, work primarily through surface-level convective heating but at intensities that trigger a more dramatic whole-body heat stress response — including a greater cardiovascular "workout" effect.

Detoxification: Promising but Nuanced

Perhaps no topic in the sauna world is more marketed — and more contested — than detoxification.

The theoretical basis for sweat-based detoxification is real. Sweat glands are legitimate excretory organs capable of eliminating certain heavy metals and environmental toxins. A 2023 study published in the Journal of Environmental Science and Health analyzed sweat from 22 participants using infrared saunas and found elevated concentrations of toxic elements — including aluminum, arsenic, cadmium, lead, and mercury — compared to sweat from conventional exercise or wet saunas.⁹ The deep tissue heating of far-infrared saunas appears to mobilize stored toxins from soft tissues more effectively than surface-level heat.

A study by Genuis et al. (2011) found that sweat can enhance the excretion of metals like aluminum (3.75-fold), cadmium (25-fold), and lead (17-fold) compared to urine.¹⁰

However, important caveats apply. WebMD notes that for people without a diagnosed heavy metal burden or known toxic exposure, the detoxification benefits of sauna use may be overstated — the liver and kidneys remain the primary organs of detoxification for most people.¹¹ Cleveland Clinic's Dr. Melissa Young echoes this, noting that detoxification research is "still in its infancy."²

Bottom line: Both sauna types induce sweating and may assist in eliminating certain heavy metals — with emerging evidence that infrared saunas may be particularly effective for this purpose. However, sauna detoxification should be seen as a supplement to healthy liver and kidney function, not a replacement.

Mental Health and Stress Relief

Both sauna types appear to offer meaningful mental health benefits, and the mechanisms are largely shared.

Regular heat exposure stimulates the release of endorphins, reduces levels of the stress hormone cortisol, and promotes a favorable balance between the sympathetic (fight-or-flight) and parasympathetic (rest-and-digest) nervous systems. A 2024 comprehensive review in the journal

Temperature found that regular sauna bathing is linked to improved well-being, reduced stress, and greater relaxation.¹²

A Global Sauna Survey published in Complementary Therapies in Medicine (2019) — which included users of both traditional and infrared saunas — found that the vast majority of regular sauna bathers reported improvements in sleep quality, mood, and overall sense of well-being.¹³

For infrared saunas specifically, an exploratory 2024 study from UCSF combining infrared sauna therapy with cognitive behavioral therapy found that 11 of 12 participants no longer met diagnostic criteria for major depressive disorder after the combined treatment.¹⁴

Finnish sauna data on mental health is also compelling: the same large cohort studies tracking cardiovascular outcomes found that men who used the sauna 4–7 times per week had a dramatically reduced risk of developing psychosis compared to once-weekly users.⁵

Bottom line: Both sauna types appear to meaningfully support mental health through overlapping physiological pathways. Research on infrared saunas in clinical mental health contexts is emerging and shows early promise.

Skin Health

Infrared saunas have a particular advantage when it comes to dermatological benefits. The infrared wavelengths used — particularly near-infrared — penetrate the skin at a cellular level, where they can stimulate collagen production, improve circulation to skin tissues, and promote a process called photobiomodulation (cellular repair stimulated by light).

A study published in Yonsei Medical Journal (2006) found that repeated infrared radiation improved skin texture, reduced fine lines, and supported skin health markers beyond what heat alone would produce.¹⁵

Traditional sauna use also benefits the skin through improved circulation and the flushing effect of intense sweating, but lacks the direct photobiomodulatory effects of infrared light.

Safety Considerations

Traditional wood-fire saunas carry a higher risk of heat-related adverse events due to their extreme temperatures. Absolute contraindications include unstable angina, recent myocardial infarction (within 3–6 months), severe aortic stenosis, and decompensated heart failure.¹ Alcohol combined with sauna use has been identified as a major contributing factor in sauna-related deaths, accounting for a significant proportion of adverse events.³

Infrared saunas, operating at lower temperatures, are generally better tolerated by a wider range of people, including older adults and those with some cardiovascular conditions. However, they are not without risk — heat stress, dehydration, and orthostatic hypotension can occur in both types, particularly in vulnerable populations.

For both sauna types, the Mayo Clinic recommends staying well-hydrated, limiting sessions to 15–20 minutes, and avoiding sauna use when acutely ill, pregnant (without medical guidance), or intoxicated.

At Fyre Sauna, our staff are always on hand to help first-time guests understand safe session protocols within our saunas.

Side-by-Side Comparison

At Fyre Sauna, guests often ask us to summarize the differences at a glance. Here's how the two stack up across the most important health categories:

Feature	Wood-Fire (Finnish) Sauna	Infrared Sauna
Temperature	80–100°C (176–212°F)	43–60°C (110–140°F)
Heat mechanism	Heats surrounding air	Directly heats the body via infrared light
Cardiovascular evidence	Extensive (20+ year cohort studies)	Moderate (shorter-term clinical trials)
Comfort/tolerability	Intense; less suitable for heat-sensitive individuals	Gentler; more accessible
Pain & recovery	Good evidence	Strong short-term evidence
Detoxification	Moderate evidence	Emerging evidence, possibly superior
Skin health	General (circulation-based)	Enhanced (photobiomodulation + circulation)
Mental health	Strong epidemiological evidence	Promising clinical trial data
Risk level	Higher (extreme heat)	Lower (moderate heat)

The Bottom Line

Both infrared and wood-fire saunas offer genuine, science-supported health benefits. The evidence for traditional Finnish sauna use — particularly for cardiovascular mortality, dementia prevention, and longevity — is deeper and more robust, built on decades of large-scale prospective studies. However, the infrared sauna's lower operating temperature makes it more accessible to a wider range of people, and emerging research suggests it may have distinct advantages in areas like post-exercise recovery, detoxification of heavy metals, skin health, and tolerability for heat-sensitive individuals.

The "best" sauna is the one you'll actually use regularly. Frequency matters enormously — the most dramatic health benefits in the research literature are consistently associated with sauna use of 4 or more times per week.

As always, if you have a pre-existing cardiovascular or metabolic condition, consult your physician before starting or significantly increasing sauna use.

References

1. Hussain, J., & Cohen, M. (2018). Clinical Effects of Regular Dry Sauna Bathing: A Systematic Review. Evidence-Based Complementary and Alternative Medicine, 2018, 1857413. https://doi.org/10.1155/2018/1857413

2. Pojednic, R. (2026). Discover the Science Behind Infrared Sauna Benefits. Restore Health Blog. https://www.restore.com/blog/infrared-sauna-benefits

3. Laukkanen, T., Khan, H., Zaccardi, F., & Laukkanen, J. A. (2015). Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events. JAMA Internal Medicine, 175(4), 542–548. https://doi.org/10.1001/jamainternmed.2014.8187

4. Laukkanen, T., Kunutsor, S. K., Khan, H., Willeit, P., Zaccardi, F., & Laukkanen, J. A. (2018). Sauna bathing is associated with reduced cardiovascular mortality and improves risk prediction in men and women: a prospective cohort study. BMC Medicine, 16(1), 219. https://doi.org/10.1186/s12916-018-1198-0

5. Laukkanen, J. A., Laukkanen, T., & Kunutsor, S. K. (2018). Cardiovascular and Other Health Benefits of Sauna Bathing: A Review of the Evidence. Mayo Clinic Proceedings, 93(8), 1111–1121. https://doi.org/10.1016/j.mayocp.2018.04.008

6. Beever, R. (2009). Far-infrared saunas for treatment of cardiovascular risk factors: Summary of published evidence. Canadian Family Physician, 55(7), 691–696. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2718593/

7. Lee, E., Kolunsarka, I., Kostensalo, J., Ahtiainen, J. P., Haapala, E. A., Willeit, P., Kunutsor, S. K., & Laukkanen, J. A. (2022). Effects of regular sauna bathing in conjunction with exercise on cardiovascular function: a multi-arm randomized controlled trial. American Journal of Physiology – Regulatory, Integrative and Comparative Physiology, 323(3), R289–R299. https://doi.org/10.1152/ajpregu.00076.2022

8. Ahokas, E. K., Ihalainen, J. K., Hanstock, H. G., Savolainen, E., & Kyröläinen, H. (2023). A post-exercise infrared sauna session improves recovery of neuromuscular performance and muscle soreness after resistance exercise training. Biology of Sport, 40(3), 681–689. https://doi.org/10.5114/biolsport.2023.119289

9. Kuan, W. H., et al. (2023). Comparative analysis of toxic elements in sweat from infrared sauna versus exercise. Journal of Environmental Science and Health. [As cited in: https://www.hightechhealth.com/how-far-infrared-saunas-detoxification/]

10. Genuis, S. J., Birkholz, D., Rodushkin, I., & Beesoon, S. (2011). Blood, Urine, and Sweat (BUS) Study: Monitoring and Elimination of Bioaccumulated Toxic Elements. Archives of Environmental Contamination and Toxicology, 61(2), 344–357. https://doi.org/10.1007/s00244-010-9611-5

11. WebMD Medical Reference. (2024). Infrared Saunas: What Are the Health Benefits? https://www.webmd.com/balance/health-benefits-of-infrared-saunas

12. Laukkanen, J. A., & Kunutsor, S. K. (2024). The multifaceted benefits of passive heat therapies for extending the healthspan: A comprehensive review with a focus on Finnish sauna. Temperature: Multidisciplinary Biomedical Journal, 11(1), 27. https://doi.org/10.1080/23328940.2023.2300623

13. Hussain, J. N., Greaves, R. F., & Cohen, M. M. (2019). A hot topic for health: Results of the Global Sauna Survey. Complementary Therapies in Medicine, 44, 223–234. https://doi.org/10.1016/j.ctim.2019.03.012

14. Carnahan, J. (2025, December). Infrared Saunas: The Science-Backed Path to Enhanced Detoxification and Optimal Health. DrJillHealth.com. https://www.jillcarnahan.com/2025/12/01/infrared-saunas-science-detox/ [Citing 2024 UCSF research]

15. Lee, J. H., Roh, M. R., & Lee, K. H. (2006). Effects of Infrared Radiation on Skin Photo-Aging and Pigmentation. Yonsei Medical Journal, 47(4), 485–490. https://doi.org/10.3349/ymj.2006.47.4.485

This article is written by the team at Fyre Sauna and is for informational purposes only. It does not constitute medical advice. Always consult a qualified healthcare provider before making changes to your health routine, especially if you have pre-existing medical conditions. Interested in experiencing both sauna types or building your own? Contact us to book a session or discuss a custom home sauna build.