How does infrared sauna work is worth understanding before buying one, because the mechanism explains every difference between an infrared cabin and a traditional sauna: why the air stays cool, why you still sweat, why there is no steam, and why panel placement matters more than the wattage on the box.
Radiant heat, not hot air
The panels emit infrared radiation, which is simply light at wavelengths longer than you can see. It travels across the cabin and is absorbed by whatever it lands on, including you, warming that object directly. The air in between is barely heated because air absorbs very little of it, which is why the cabin can feel mild while you are sweating.
Why you sweat at a lower temperature
Your body responds to its own rising temperature rather than to the thermometer on the wall. Absorbing radiation directly raises skin and near-surface tissue temperature efficiently, so the sweat response starts at an air temperature far below what a traditional sauna needs. The sweat is comparable; the room is not.
Near, mid and far
Far infrared is the longest wavelength, absorbed right at the skin, and it is what the overwhelming majority of cabins use. Mid penetrates slightly further, near further still and is what full spectrum cabins add, usually with one extra lamp. Claims that deeper penetration produces specific health effects are marketed confidently and are not established.
Why placement beats wattage
Radiation travels in straight lines from the emitter, so a panel warms what it faces and nothing else. Panels behind the bench warm your back and leave your front cool, which no amount of extra power fixes. That is why panel area and where the panels sit are the specification to read, and total watts tells you mostly about the electricity bill.
Questions people ask about how does infrared sauna work
Why does the cabin stay cool?
Air absorbs very little infrared. The radiation passes through it and is absorbed by you, so you warm up while the air does not.
Is infrared the same as microwaves or UV?
No. Infrared is light at wavelengths just longer than visible red. It warms surfaces it lands on and does not ionise anything.
Does full spectrum penetrate deeper?
Near infrared does penetrate further than far infrared. That specific health effects follow from it is not established.