Fever or pyrexia is a common clinical phenomenon. Among survivors of traumatic brain injury, it may appear immediately after injury, signal the presence of infection or reflect dysfunction of the thermoregulatory system. Management of pyrexia must be distinguished from measures that seek to identify and remove the putative cause of fever. Guidelines for decision making regarding the nursing management of patients with fever are presented. Given the potential benefit of fever, the ability of most patients to tolerate temperature elevations and the adverse effects, costs and discomforts associated with therapy, our habit of automatically reducing temperature should be examined.