A healthy organism reacts to the threat of illness with regulated increases in temperature, progressing in acute cases to a high fever which can trigger an enhanced immune response effectively defeating the infection. Body temperature plays a crucial role in the most complex regulation of the immune system. Fever can be considered as being a temporary "special immune program" of nature. Fever as the reaction to an infection can not be equated with hyperthermia as a physical heating of the body. Nevertheless, the increase of systemic body temperature by therapeutic hyperthermia can result in a sustained stimulation of otherwise inhibited immune activity in cases of susceptibility to infections, in chronic infections, as well as in anti-tumor immune response. On the other side, fever-range hyperthermia can have an anti-inflammatory effect in case of chronic inflammation and auto-immune diseases. Hyperthermia can help to "reset" the regulation of the immune system overcoming chronic pathologic dysfunctions of a too low or too high immune activity. Recent comprehensive reviews on the immune effects of fever and of hyperthermia are OPEN ACCESS available:

Beside of the immune effects whole-body hyperthermia has strong perfusional effects and is, among others, effective in relaxation even of deep-seated muscle layers, reducing chronic pain disorders. Because of the simple principle and the natural background whole-body hyperthermia has got a history of thousands of years and can be considered as one of the most ancient medical methods of mankind, reported in various culture areas and used for a wide variety of diseases - look at "History of Fever therapy and Hyperthermia". Based on this history, whole-body hyperthermia in the range of fever has proven safety and a very low risk of adverse effects if basic criteria of indications and contra-indications are followed. It is an obligation to save and develop this precious tradition by maintaining and spreading it as a basic tool of natural healing concepts and an adjunct to conventional therapies. Moreover, clinical studies must be conducted to increase the scientific level of evidence.

The three levels of whole-body hyperthermia (WBH)

Subclinical, "mild" WBH: till 38,5°C
Fever-range, "moderate" WBH: 38,5 - 40,5°C
Extreme WBH: > 40,5 - 42°C