You receive a discharge summary for Sammy who is a three-year-old boy who was seen by a member of the paediatrics team following his first febrile seizure. From the summary you can see that the seizure lasted four minutes, had no atypical features and an uncomplicated post-ictal phase. The seizure was triggered by a Urinary Tract Infection (follow-up for this has been arranged). The discharge summary has requested you see Sammy to ensure he is responding well to antibiotics and to further explain what febrile seizures are. Which of the following statements about febrile seizures is true?