The concept that fevers can improve the condition of patients with certain medical and psychiatric diseases dates back to Hippocrates. Over the centuries, it has been observed that fevers and infectious agents have been beneficial for a broad spectrum of diseases, including neurologic conditions such as epilepsy and psychiatric illnesses including melancholy and psychosis. Interest in the concept of fever as a treatment for disease, termed pyrotherapy or pyretotherapy, peaked in the late 1800s and early 1900s thanks to the Nobel Prize winning work of Julius Wagner-Jauregg for his studies with malaria therapy for general paralysis of the insane, now more commonly referred to as neurosyphilis. The use of inoculations of infectious agents for their fever-inducing effects in the treatment of neurosyphilis quickly spread throughout the world, and, by the 1920s, it was considered by many to be the treatment of choice for neurosyphilis as well as other psychotic disorders. However, with the discovery of penicillin for the treatment of syphilis, which coincided with the advent of convulsion-oriented practices including electroconvulsive therapy and insulin coma for the treatment of psychotic disorders, pyrotherapy soon lost favor among psychiatrists and, since the 1950s, it has largely been overlooked by the scientific community. In this article, the authors provide a brief literature review of the history of pyrotherapy and present a case report of a woman with schizoaffective disorder and severe psychotic symptoms who experienced a remarkable resolution of psychotic symptoms following an episode of bacteremia with high fever.