Panels warm your skin directly while the air stays around 45–65°C. Gentler than a Finnish sauna, with a much smaller evidence base of its own.
An infrared sauna uses carbon or ceramic panels that emit infrared radiation, warming your skin directly while the air stays much cooler than in a traditional sauna, usually around 45–65°C (113–150°F). 'Near', 'mid' and 'far' describe the wavelength band; 'full-spectrum' cabins combine them, often adding red or near-infrared LEDs. The category also covers portable pods and infrared blankets you lie in.
It feels gentler, which is the appeal, and it's also why the big Finnish sauna findings don't transfer automatically. Those came from ~80°C rooms; minute for minute, an infrared session is usually a lighter heat load.
The best-studied infrared protocol is Japanese 'Waon therapy' (15 minutes at 60°C, then 30 minutes resting under blankets) in people with heart failure. Small trials and one multicentre randomized trial reported better symptoms and walking distance, though the main blood-marker endpoint didn't reach significance. A 2018 review of 40 dry-sauna studies found mostly small, varied trials. There are no long-term outcome studies of infrared use in healthy people; a Japanese cohort linking near-daily hot baths to less cardiovascular disease hints that heat dose, not the device, is what matters.
In 149 hospitalized patients with advanced heart failure, 10 days of daily far-infrared sauna (60°C for 15 minutes, then 30 minutes under blankets) improved symptom class, 6-minute walk distance and heart size on X-ray versus controls; the change in the primary blood marker (BNP) was not statistically significant. No serious adverse events.
Across 40 studies with 3,855 participants, only 13 were randomized trials and most were small (under 40 people). Outcomes were varied and mostly reported benefits; the authors called for larger, higher-quality studies to establish effects and safe doses.
In 30,076 Japanese adults aged 40–59 followed for about 20 years, near-daily hot tub bathing was associated with 28% lower risk of cardiovascular disease than bathing 0–2 times a week (HR 0.72), with no association for sudden cardiac death.