Pediatricians are frequently taught that a rapid rise in temperature is responsible for causing a febrile seizure; yet there are no clinical data to support this hypothesis. The few experimental data are based on hyperthermia-induced seizures in animals and are of no clear relevance to naturally occurring fevers and accompanying seizures. Further, the experimental findings are not consistent across studies. By contrast, there is substantial evidence indicating that the height of temperature plays a role in eliciting a febrile seizure. Although febrile seizures are now recognized as benign and, in general, a disorder that should not be treated with chronic anticonvulsant therapy, an understanding of how fevers lead to febrile seizures may be useful for evaluating the appropriateness and efficacy of treatments that involve intermittent therapy given at the time of fever.