In the clinical practice guidelines published by the American Academy of Pediatrics (AAP) in 2011, FS is defined as a convulsive seizure (temperature ≥38°C) in the febrile state in children from 6 months of age to 5 years of age, without evidence of CNS infection and a clear etiology, and without a history of fever-free convulsions. It follows that in children with fever with convulsions at a given age, FS can be diagnosed only if intracranial infection and other causes of convulsive seizures are excluded. FS usually occurs within 24 h of fever, with up to 21% of FS occurring within 1 h of fever. In particular, it should be noted that some FS have convulsions as the first symptom, and it has been reported in the literature that these patients can account for 25% to 50% of children with FS. Convulsive episodes that occur within 3 d of fever or later should generally not be considered as FS, and other causes of convulsions should be sought.