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 different types, 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, an increased heart rate 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) - The Skin Healer: With the shortest wavelength, it penetrates just below the skin's surface to stimulate cellular regeneration, support wound healing, enhance collagen production and boost circulation at a cellular level. It is best for skin rejuvenation and visible improvements in skin tone and elasticity.
- Mid-Infrared (MIR) - The Muscle and Joint Reliever: It reaches into soft tissues and muscles to improve circulation, ease pain and stiffness in joints and muscles, support metabolism and reduce inflammation. It is best for athletic recovery, chronic pain and stiffness.
- Far-Infrared (FIR) - The Deep Detoxifier: With the longest wavelength, it penetrates deepest into the body - up to 1.5 inches into tissue - supporting the body's natural cooling processes through sweating, promoting deep relaxation, cardiovascular function and overall wellbeing.
A full-spectrum infrared sauna combines near, mid and far-infrared wavelengths in a single session. This approach delivers comprehensive therapeutic benefits, from skin health and anti-ageing to pain relief, detoxification and deep relaxation. [3]
Ok But, How Does Infrared Heat Actually Work?
In this section we go are bit deeper into the physics and science behind infrared saunas so bare with us. If that's too much information for you at the moment, you can skip to the the health benefits section summary.
Infrared energy is absorbed directly by water molecules and biological tissues within the body. This causes those tissues to warm from within, producing physiological responses long before the surrounding air reaches the temperatures associated with conventional saunas.
As your core temperature begins to rise, your body responds in much the same way it would during moderate exercise. Blood vessels dilate (vasodilation), heart rate increases, and blood flow is redirected towards the skin to help regulate body temperature. This enhanced circulation improves the delivery of oxygen and nutrients to muscles and tissues while supporting the removal of metabolic waste products.
Heat Shock Proteins: Your Cells' Natural Repair System
One of the most fascinating effects of heat exposure is the production of heat shock proteins (HSPs).
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 increase the production of these protective proteins.
Heat shock proteins act like cellular quality-control specialists. They help repair damaged proteins, prevent newly formed proteins from folding incorrectly, protect cells from stress-induced damage, and assist in maintaining normal cellular function.
By preserving protein integrity and helping cells recover from physiological stress, heat shock proteins are thought to contribute to exercise recovery, improved resilience to repeated stressors and healthy ageing. While many of these mechanisms are well established in laboratory research, scientists continue to investigate how they translate into long-term health benefits in humans. [8]
Improved Blood Flow and Nitric Oxide
Infrared heat also stimulates the release of nitric oxide, a naturally occurring signalling molecule that relaxes and widens blood vessels.
This process, known as vasodilation, increases circulation throughout the body. Improved blood flow delivers more oxygen and nutrients to tissues while helping transport carbon dioxide and other metabolic by-products away from muscles.
For many people, this improved circulation contributes to reduced muscle soreness, greater joint mobility and a feeling of relaxation following a sauna session.
Cellular Energy and Mitochondrial Function
Near-infrared light has been shown in laboratory and clinical photobiomodulation studies to interact with cytochrome c oxidase, a key enzyme within the mitochondrial electron transport chain.
This interaction is associated with increased ATP production, nitric oxide signalling and cellular repair pathways.
While these mechanisms are well established in photobiomodulation research, scientists are still investigating the extent to which they contribute to the health effects observed during full-spectrum infrared sauna sessions, where heat-induced physiological responses remain the primary mechanism. [6]
A Hormetic Response
Scientists often describe infrared sauna therapy as creating a form of hormesis, a beneficial adaptation to a mild, controlled stress.
Just as exercise challenges the body and stimulates positive adaptations over time, carefully controlled heat exposure activates a range of protective responses. These include increased circulation, heat shock protein production, improved cardiovascular efficiency and enhanced thermoregulation.
Rather than causing harm, this temporary heat stress activates a range of adaptive physiological responses, including increased heat shock protein production, improved vascular function and enhanced thermoregulation. Over time, repeated exposure may strengthen many of the body's natural repair and maintenance processes.
Long-term observational studies have associated regular sauna bathing with improved cardiovascular health, reduced cardiovascular mortality and enhanced overall wellbeing, although some proposed benefits require further clinical research. [7]
Health Benefits: What the Science Says
The health benefits of infrared sauna use are supported by a growing body of scientific research.
- Muscle Recovery and Athletic Performance: A 2025 study from the University of Jyväskylä in Finland found that infrared sauna exposure after exercise helped prevent decline in jump performance, reduced muscle soreness and improved perceived recovery. Regular use enhanced loaded jump performance and maximum sprint speed. [4]
- Cardiovascular Health: Multiple studies have examined infrared sauna use for various health conditions, including high blood pressure, heart failure, dementia, Alzheimer's disease, headache, type 2 diabetes and arthritis. The heat exposure helps blood vessels expand, improving circulation and potentially lowering blood pressure. [5]
- Pain Relief: Research points to benefits for alleviating pain, reducing stiffness and improving mobility in patients with rheumatoid arthritis, ankylosing spondylitis and osteoarthritis. Infrared sauna use has also been associated with relief from chronic pain, chronic fatigue syndrome and depression.
- Cellular and Metabolic Effects: A 2024 study published in the Journal of Physiology found that 8 weeks of infrared sauna use (3 times per week, 45 minutes at ~60°C) strongly increased muscle tissue capillarisation - the density of tiny blood vessels that deliver oxygen to muscles.
- Mental Health and Sleep: Infrared sauna sessions have been shown to lower cortisol levels, support deep restorative sleep and improve heart rate variability. One study found that infrared sauna sessions combined with cognitive behavioural therapy led to a statistically significant reduction in depression symptoms.
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.
Infrared heat therapy works by gently raising core body temperature, encouraging sweating and increasing blood flow through the dilation of blood vessels.
Red light therapy (photobiomodulation) uses specific wavelengths of light that are thought to support cellular energy production (ATP) within the mitochondria and may help support the body's natural repair processes. As the two therapies work through different mechanisms, they are often used together as part of a wellness and recovery routine.
For a high-quality red light therapy device, look for:
- Wavelengths: 660nm (red) for skin benefits and 850nm (near-infrared) for deep tissue.
- Power: High irradiance (mW/cm²) - therapeutic devices deliver focused, powerful light.
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
