Sauna is the only bath in the world in which both dry and damp air is present at the same time. It is the body's natural way to cleanse itself through perspiration. The high heat (average of 180° F) and the low humidity (about 25%) create an environment which promotes over-all perspiration and the deep cleansing of pores.
Saunas are safe for most people so long as the sauna user follows a few simple rules:
Stay inside the sauna for no more than 30 minutes at a time.
Lie down or sit for at least 10 minutes after using the sauna. Make sure you drink plenty of mineralized water before and after the sauna. Add minerals or juice to your water if it is mineral-free. It is also a good idea to add extra sea salt to your diet to replace minerals lost through sweating in the sauna.
Use the sauna under supervision if you have a chronic condition. If you are debilitated or very sensitive to heat, begin with a shorter period of time in the sauna. The presence of an attendant or friend in the sauna can also be very helpful.
If you use the sauna once a day, the evening is probably the best time. If you are ill, however, the morning may prove a better time because your energy levels are higher. Using the sauna less often is also acceptable if you are just beginning or if your goal is to maintain your health. If you have a condition which is very debilitating, begin with using the sauna once a week. You may gradually work your way up to using the sauna daily as you feel able.
While using the sauna, it is important to take frequent showers in order to cool down as well as to remove substances from the skin and prevent their re-absorption.