An infrared sauna is a sauna that heats its occupants with infrared heaters that emit infrared radiant heat. Unlike traditional Finnish Saunas, infrared saunas do not use steam, but instead use infrared radiation to directly heat the user. Why use an infrared sauna - A moderately conditioned person can easily sweat off 500 grams in a sauna, consuming nearly 300 kcal, which is equivalent to running 2-3 miles. A heat-conditioned person can easily sweat off 600-800 kcal with no adverse effects. While the weight of the water loss can be regained by drinking water, the calories consumed will not be. The source of this energy is then confused to be body energy stores, while the source is in fact the excessive heat absorbed from the sauna. The body reacts to the excess heat by increasing perspiration. Your metabolism is elevated and your body is spending calories cooling itself.