Pyrotherapy (artificial fever, therapeutic fever) is a method of treatment by raising the body temperature or sustaining an elevated body temperature (caused by a fever). In general, the body temperature was maintained at 41° Celsius(105° Fahrenheit) . Many diseases were treated by this method in the first half of the 20th century. In general, it was done by exposing the patient to hot baths, warm air, or (electric) blankets.
One example is the malariotherapy, the treatment of syphilis by the introduction of malaria, for which Julius Wagner-Jauregg won Nobel Prize for Medicine in 1927.
The general paresis of the insane caused by neurosyphilis was effectively overcome by the method.
Pyrotherapy was also employed in psychiatry. Of note here is the use of sulfozinum and pyrogenal that was relatively widespread in Soviet psychiatry.