The room is not supposed to be overly hot.
"Unlike a traditional sauna, infrared saunas don’t heat the air around you. Instead, they use infrared lamps (that use electromagnetic radiation) to warm your body directly.
“These saunas use infrared panels instead of conventional heat to easily penetrate human tissue, heating up your body before heating up the air,” explains physical therapist, Vivian Eisenstadt, MAPT, CPT, MASP.
An infrared sauna can operate at a lower temperature (usually between 120˚F and 140˚F) than a traditional sauna, which is typically between 150˚F and 180˚F.
Manufacturers claim that in an infrared sauna, only about 20 percent of the heat goes to heat the air and the other 80 percent directly heats your body."