Infrared saunas have become a popular wellness tool, offering a different experience from traditional saunas. Instead of heating the air around you, they use light to heat your body directly. This guide covers how they work, the research on their health benefits, what to consider when buying one and how to complement your sauna with red light therapy.
Sauna by the Numbers
Sauna bathing is not simply a passing wellness trend. In Finland, where sauna culture has been part of everyday life for centuries, millions of people continue to make regular sauna sessions part of their routine.
- 3.2 million saunas for a population of around 5.5 million people.
- A peer-reviewed survey found that 59% of Finnish adults use a sauna at least once every week.
- Only 6.8% of respondents said they never use a sauna.
These figures show how deeply sauna bathing is embedded in Finnish culture and help explain why it remains one of the most widely studied heat-based wellness practices in the world.
Of course, the saunas found in Finland are traditionally heated using wood or electric stoves, not infrared technology. Infrared saunas are a modern evolution that uses infrared light to warm the body more directly rather than heating the surrounding air. This creates a different sauna experience while still providing the gentle warmth and relaxation that have made sauna bathing a cherished wellness ritual for generations.
What Is an Infrared Sauna?
An infrared sauna uses light to create heat. While a traditional sauna warms the air, which then warms your body, an infrared sauna heats your body directly without significantly warming the air. [1] Think of it like standing in the sun on a cool day - you feel warm from the sunlight even when the air temperature is low. This method of radiant heat allows infrared saunas to operate at much lower temperatures, typically between 49°C–60°C, compared to traditional saunas, which reach 66°C–82°C. This lower temperature can be more tolerable while still promoting vigorous sweating and deep relaxation. [2]
The Three Types of Infrared: Near, Mid and Far
Infrared light spans a spectrum of wavelengths and each type penetrates the body differently, offering distinct benefits.
- Near-Infrared (NIR): With the shortest wavelength, near-infrared light is absorbed close to the skin's surface. It is commonly used in infrared wellness products and is often associated with skin-focused applications.
- Mid-Infrared (MIR): Mid-infrared wavelengths reach deeper into soft tissues than near-infrared, making them a popular choice in full-spectrum infrared saunas for those seeking a balanced heat experience.
- Far-Infrared (FIR): With the longest wavelength, far-infrared provides the deep, gentle warmth most commonly associated with infrared saunas. It is designed to warm the body gradually and encourage a comfortable sweating experience.
A full-spectrum infrared sauna combines near, mid and far-infrared wavelengths in a single session, allowing users to experience the full range of infrared heat produced by each wavelength.
Many people choose full-spectrum infrared saunas as part of their regular wellness routine for relaxation, recovery and overall wellbeing. Individual experiences may vary.[3]
Ok But, How Does Infrared Heat Actually Work?
In this section, we'll take a slightly deeper look at the science behind infrared saunas. If you'd rather skip the technical details, feel free to jump straight to the summary below.
Infrared energy is absorbed by water molecules and biological tissues within the body, gently warming the body without relying solely on heating the surrounding air. This is one of the key differences between infrared and traditional saunas.
As your body warms, it responds in ways that are similar to other forms of heat exposure. Heart rate may increase, blood vessels can widen (vasodilation), and blood flow towards the skin may increase as the body works to regulate its temperature.
Heat Shock Proteins: The Body's Response to Heat
One area of ongoing scientific research is the production of heat shock proteins (HSPs) during heat exposure.
Heat shock proteins are specialised molecules found in virtually every cell in the body. When cells experience mild heat stress, such as during an infrared sauna session, they can increase the production of these protective proteins.
Heat shock proteins help maintain normal cellular function by assisting with protein folding, supporting the repair or removal of damaged proteins and helping cells respond to physiological stress.
Researchers continue to study the role of heat shock proteins and how they may contribute to the body's natural response to heat and exercise. While these cellular mechanisms are well established, their long-term effects on overall health and wellbeing continue to be investigated. [8]
Improved Blood Flow and Nitric Oxide
Heat exposure is associated with the release of nitric oxide, a naturally occurring signalling molecule involved in regulating blood vessel function.
Nitric oxide helps blood vessels relax and widen, a process known as vasodilation. As the body warms, blood flow towards the skin typically increases as part of its normal temperature regulation process.
Many people report feeling relaxed after an infrared sauna session, although individual experiences may vary.
Cellular Energy and Mitochondrial Function
Near-infrared light has been studied in laboratory and clinical photobiomodulation research for its interaction with cytochrome c oxidase, an enzyme involved in cellular energy production within the mitochondria.
Research suggests this interaction may influence cellular signalling pathways, including those related to ATP production and nitric oxide. These mechanisms are well documented in photobiomodulation research, although they continue to be investigated in the context of full-spectrum infrared saunas, where heat remains the primary source of physiological effects. [6]
A Hormetic Response
Scientists often describe heat exposure as a form of hormesis, the idea that a mild, temporary stress can trigger the body's natural adaptive responses.
Similar to exercise, controlled heat exposure encourages the body to regulate its temperature through normal physiological processes. These responses include changes such as increased heart rate, heat shock protein production and thermoregulation.
Researchers continue to study how repeated heat exposure influences these natural responses over time. While many of the underlying biological mechanisms are well understood, their long-term contribution to overall health and wellbeing remains an active area of scientific research. [7]
What Does the Research Say?
Research into infrared sauna use is continuing, with studies investigating its effects across a range of areas. While some findings are promising, results can vary between individuals, and further research is needed to better understand the long-term effects.
- Exercise and Recovery: Some studies have investigated infrared sauna use following exercise. For example, a 2025 study from the University of Jyväskylä in Finland reported improvements in measures such as perceived recovery and post-exercise performance compared with control conditions. More research is needed to confirm these findings across different populations. [4]
- Cardiovascular Function: Heat exposure has been widely studied for its effects on the cardiovascular system. Research has explored infrared sauna use in a variety of settings, including its influence on blood vessel function and circulation, although evidence for specific health outcomes continues to be evaluated. [5]
- Cellular Responses: A 2024 study published in the Journal of Physiology investigated the effects of eight weeks of infrared sauna use on skeletal muscle and reported changes in muscle capillarisation. Researchers continue to study how these physiological adaptations relate to health and physical performance.
- Wellbeing: Researchers have also explored the relationship between infrared sauna use and measures of wellbeing, including relaxation, sleep and mood. While some studies have reported positive findings, additional high-quality clinical research is needed before firm conclusions can be drawn.
Traditional Sauna vs. Infrared Sauna: Key Differences
The key advantage of infrared is that it allows a more intense sweat at a lower temperature, potentially allowing for longer sessions. Manufacturers estimate that in an infrared sauna, only about 20% of the heat goes to warming the air - the other 80% directly heats your body.
What to Look for When Buying an Infrared Sauna
- Full-Spectrum vs. Far-Infrared Only: A full-spectrum sauna delivers all three wavelengths for comprehensive benefits.
- Heater Quality and Coverage: More heater surface area generally means more even heat distribution.
- Low EMF (Electromagnetic Field) Emissions: This is a critical factor. In an infrared sauna, you sit within inches of multiple powered panels. Look for saunas with integrated EMF cancellation technology built into the heater panels. Some premium brands achieve EMF levels as low as 2.5 milligauss measured directly on the heaters.
- Wood Quality and Construction: The wood used, such as Canadian Hemlock, offers excellent heat retention, structural stability and durability.
- Chromotherapy vs. True Red Light Therapy: Many saunas advertise "red light" or "chromotherapy" features. Chromotherapy uses a wide range of colored lights for mood and ambience and is not the same as true red light therapy. True red light therapy (photobiomodulation) uses specific, scientifically-studied wavelengths - typically 660nm (red) and 850nm (near-infrared) - at therapeutic power levels.
Safety Considerations and Contraindications
- Who Should Avoid Infrared Saunas: Pregnant women, individuals with haemophilia or bleeding disorders, those with fever or heat insensitivity, people with unstable heart conditions or cardiovascular disease, those with kidney disease and individuals under the influence of alcohol.
- Best Practices for Safe Use: Stay well-hydrated, start with shorter sessions (15–20 minutes) and gradually increase and listen to your body.
Dive Further
Read about the different benefits of infrared saunas and cold plunges.
A More Accessible Way to Experience Infrared Heat
If a full-size infrared sauna isn't practical because of budget or available space, an infrared sauna blanket offers a convenient alternative. the FLOE Infrared Sauna Blanket delivers the benefits of far infrared heat therapy in a compact, portable design that can be used from the comfort of home. It requires no installation, folds away neatly after use and provides an accessible way to incorporate regular heat therapy into your wellness routine.
Supercharging Your Results: Adding Red Light Therapy to Your Routine
While infrared heat therapy offers many wellness benefits on its own, combining it with a dedicated red light therapy device can provide additional support for your overall recovery and wellbeing.
Read more about red light therapy in our article 'Finding the Right Device for Your Lifestyle'
Disclaimer: This article is for informational purposes only and does not constitute medical advice. Always consult with a healthcare professional before starting any new wellness therapy, especially if you have underlying health conditions or are pregnant.
References
[1] Mayo Clinic https://www.mayoclinic.org/healthy-lifestyle/consumer-health/expert-answers/infrared-sauna/faq-20057954
[2] Healthline https://www.healthline.com/health/infrared-sauna-benefits
[3] Sanctuary wellness spa https://sanctuarywellnessspa.com/understanding-infrared-saunas-far-mid-near-full-spectrum-infrared/
[4] Eurek alert: Infrared sauna shows promising benefits for team-sport athletes https://sciencesources.eurekalert.org/news-releases/1102774
[5] Memorial Health System https://www.mhsystem.org/health-library/faq-20057954/
[6] PubMed Centra, Mechanisms and Mitochondrial Redox Signaling in Photobiomodulation https://pmc.ncbi.nlm.nih.gov/articles/PMC5844808/
[7] JAMA Internal Medicine, Association Between Sauna Bathing and Fatal Cardiovascular and All-Cause Mortality Events https://jamanetwork.com/journals/jamainternalmedicine/fullarticle/2130724
[8] PunMed, Induction of heat shock proteins for protection against oxidative stress
