The sauna – an extreme climatic condition for the body.

By visiting a sauna, one voluntarily enters an extreme climatic condition where temperatures can range from 90 to 100 °C (194 to 212 °F), followed by a cooling down to often below 0 °C. But what exactly happens in our body during this interplay of heat and cold?
Physical changes in the sauna
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Physical changes in the sauna

Visiting a sauna is a regular ritual for many people, which not only brings relaxation and well-being, but also promises health benefits. The temperature differences to which the body is exposed during a sauna session lead to a number of remarkable changes both on the skin and inside the organism.

While the internal body temperature rises only slightly, the skin temperature can rise significantly to as high as 40 to 42 °C (104 to 107,6 °F), a phenomenon known as hyperthermia. This rise in temperature is one of the desired positive effects of sauna, as it activates and accelerates the body’s metabolism.

The role of hyperthermia and its effects on metabolism

In the sauna, the skin is strongly heated by the high ambient temperature and the direct heat radiation of the sauna stones. The blood vessels dilate to dissipate the heat and maintain the core body temperature. This process promotes increased blood flow to the skin and improves oxygen and nutrient delivery to the cells.

The hyperthermia that occurs during a sauna session also has a positive effect on metabolism. The body tries to regulate the increased body temperature by producing more sweat to remove excess heat. This flushes toxins and metabolic waste products out of the body.

At the same time, the heartbeat is accelerated to pump blood through the body faster. This increased heartbeat is a mild form of physical exercise, which in turn increases energy expenditure and stimulates fat burning. The increased metabolic activity helps the body to cleanse itself of harmful substances and gain new energy.

Sauna visits as a preventive measure against infections

The increased core body temperature reached during a sauna session is similar to the state of fever. This is an important aspect, as many pathogenic bacteria and viruses are sensitive to high temperatures. Unlike the human body, they cannot tolerate these extreme temperatures and are thus inhibited in their reproduction or even killed. In a sense, then, the sauna simulates the body’s natural defense response against potential infections.

In addition, the increased blood flow to the mucous membranes promotes defense against pathogens in the respiratory tract. Increased sweat production also helps rid the skin of bacteria. The combination of these factors strengthens the immune system and can help prevent colds and other infectious diseases.

Relaxation and stress relief

The sauna is not only for physical relaxation, but also for mental relaxation. The heat and the alternation between heat and cold lead to the release of endorphins, the so-called happiness hormones. This reduces stress hormones and increases the general feeling of well-being.


Visiting the sauna is an extreme climatic condition for our body, but it has many positive effects on the organism. The combination of heat and subsequent cooling down not only supports relaxation and general well-being, but can also serve as a preventive measure against impending infections. However, as with any health-promoting activity, the sauna should be used with caution and with consideration for individual health conditions.


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