These two terms get used as if they mean the same thing, and shops rarely help. The short version: red light therapy describes the light, a near infrared sauna describes what the light does to you when there is enough of it. One device can do both, but most cannot.
Red light therapy, in one paragraph
Red light therapy — photobiomodulation, in the literature — means exposing the body to red and near infrared light, typically somewhere between 600 and 1000 nm. Most consumer devices are LED panels. LEDs emit narrow bands, often around 660 nm in the red and 850 nm in the near infrared, and they emit almost no heat. You stand in front of one for ten or twenty minutes and you do not feel warm.
What a near infrared sauna adds
A near infrared sauna uses incandescent heat lamps instead of diodes. A filament glowing at high temperature emits a broad, continuous spectrum: visible red, near infrared, and enough radiant energy that your skin warms and you sweat. That is the difference. An LED panel gives you light. An incandescent panel gives you light and a sauna session.
The warmth also behaves differently from a conventional sauna. A Finnish sauna heats the air to 80 or 90 °C and the air heats you. A near infrared panel warms your body directly, so the room around you stays comfortable and there is nothing to pre-heat.
Where the two overlap
They overlap in wavelength. The near infrared band that LED red light panels target sits inside the spectrum an incandescent bulb produces anyway. Our bulbs peak at 850 nm, which is the same region a typical LED therapy panel aims at. The practical differences are spectrum width, intensity and heat: LEDs give you two narrow peaks and no warmth, incandescent gives you a continuous curve and a lot of warmth.
Neither approach is automatically better. They are different tools, and which one fits depends on what you actually want out of the session.
Which one fits you
An LED panel makes sense if you want short, precise light sessions with no heat, close to the skin, in a room you cannot make warm — an office, a shared flat, a space where sweating is not an option.
A near infrared sauna panel makes sense if you want the sauna part: the warmth, the sweat, the sitting-still-for-twenty-minutes part, and the near infrared light as a property of the same session rather than a separate appointment with a device.
Can one device do both?
An incandescent panel covers both uses, because the light is there whether or not you sit close enough to sweat. Sit further away and it behaves more like a light session; sit close in an enclosed space and it behaves like a sauna. An LED panel cannot go the other way — no amount of time in front of it will produce sauna heat, because the heat was never in the design.
One more practical point. LED panels need drivers, and drivers produce electric and magnetic fields that vary a lot between products. An incandescent panel has no driver electronics. Ours measures 0 V/m at 40 cm with a grounded shield, and we publish that alongside an irradiance of 70 mW/cm² at the same distance.
Keep reading
If you want the detail on how NIR, FAR infrared and LED devices differ, we wrote a full comparison. For what the research has looked at, see near infrared sauna benefits, and for the safety questions people ask most, see are near infrared saunas safe.
Our own device is a four-bulb incandescent panel built in the EU: see the near infrared sauna panel.
Red Light Sauna is a wellness and heating appliance. It is not a medical device, and we make no claims about treating, curing or preventing any illness.