Sauna bathing has long been popular in Nordic countries and has become more popular in the United States in recent years. But while many people might think that sitting in a sauna is only good for relaxation, a growing body of research suggests that regular sauna use may actually offer some impressive health benefits, too. Types of saunas A sauna is a small room filled with dry heat. Traditional Finnish saunas are common in many health clinics, day spas and recreational facilities. These are small, wood-planked rooms that are heated to a temperature somewhere between 70° to 100° Celsius (158°