Heat is the main factor, affecting us in any type of a sauna. We can be affected by hot air, hot steam, hot water and infrared rays. All the time body temperature of a person in a sauna rises up to 38-40°C. We know that such temperature kills pathogens of most diseases - bacteria and viruses. There is a reason why rising body temperature is a natural organism’s reaction to pathogens of a disease. Similar effect is done in the sauna. That’s why sauna works so well for someone who has a cold and also helps to prevent such diseases. This fact was well known by ancient doctors even at those times, when antibiotics still have not existed. They noticed that a person who went through malaria gets rid of some other diseases. However, rapid growths of body temperature could have also been very harmful for a patient. He either becomes completely healthy or passes away. However, in the sauna the element of heat belongs to humans and it can be used for body relaxation or to affect some systems of the organism.