Far infrared is the longest-wavelength band of infrared radiation, roughly 3 to 1000 micrometres. In a sauna it describes heaters that warm your body directly by radiation rather than heating the air around you. This is why a far-infrared cabin feels warm at 130°F while a traditional sauna needs 170°F or more to feel comparable.
Why it matters when you are comparing products
Air temperature is a poor comparison between the two types. A far-infrared cabin with a lower published maximum is not necessarily a milder session, because the heat reaches you by a different route.
Where this comes up
- Infrared saunas — Cabins using far-infrared or full-spectrum emitters.
- Sauna blankets — Blankets are far-infrared in a portable form factor.
Reviewed 2026-08-15