Anceno-Reyes' comments revolve around the distinction between hyperthermia and fever. Hyperthermia has been used to describe an increased body temperature resulting from thermoregulatory failure, whereas an elevated temperature generated by "appropriate" homeostatic responses is properly characterized as fever.1 These definitions are somewhat arbitrary; in fact, it may be conceptually and semantically easier to define hyperthermia as any elevation in body temperature and fever as that subset of hyperthermia resulting from intact homeostatic mechanisms.
Since all the processes involved in generating body heat have not been clearly elucidated in various disease states,1-4 it may not always be possible to place a given cause of elevated body temperature in a particular category (hyperthermia vs fever). On an operational level, however, the physician called to see a patient with an elevated temperature without an apparent cause will react as if the patient has a fever. The emphasis of my recent editorial is