People take a sauna in a cottage next to the Kemi river, Salla, Lapland, Finland. Breath taking sauna experience. A Finnish Sauna is an important part of Finnish tradition and has become popular world-wide. Every house in Finland has one. For a Finnish Sauna, a small-sized room or outdoor hut is typically heated to about 70-100 degrees Celsius (158-212 degrees Fahrenheit). While you're in there, water is gently poured on very hot stones, increasing the humidity in the room to around 20%. Saunas are used both for recreational and therapeutic purposes, with most people utilizing them as a relaxation tool that provides additional health benefits. The majority of saunas built of wood, often aromatic, that release pleasing aromas as they heat.