Probably not. It is not uncommon for children between the ages of about 6 months and 6 years to have a seizure if their temperature rises quickly to over 38.5 degrees C. 3-4% of children will have had one by the time they reach 7 years old and it often runs in families.
Usually the fit involves rhythmic movements of both arms and both legs with rolling back of the eyes. It lasts for a couple of minutes, then they go to sleep and the child is back to normal again by about 20 minutes later. The child is unconscious throughout a fit like this and it is the parents who are most upset by it. It is frightening to see your own child have a seizure. Even when they are back to their normal selves afterwards parents worry about possible brain damage or if they are at risk of having further fits or even epilepsy in the future.
Your child’s risk of having further febrile fits depends on the age he was when he had his first one, whether he fits at a fairly low temperature and whether there is a family history. Overall the risk of recurrence is 30-40%.
The vast majority of children do not go on to develop epilepsy. Those who have underlying neurodevelopmental problems, who have a family history of epilepsy and who have unusual (termed “complex”) febrile seizures have a higher risk of developing epilepsy in the future. If your child has none of the above risk factors he has no more risk of developing epilepsy than a child who has never had a febrile fit.
Short fits do not cause brain damage. Lie your child on their side if they are having a fit, do not try to prise their mouth open, you can try to cool them off a bit by removing extra layers of clothing. Call an ambulance if it is the first time thay have had a fit or if it goes on for more than a couple of minutes or if you are worried that this is not your child’s “normal” sort of febrile fit. Read a bit more on first aid for a fitting child – and indeed other problems – at http://www.firstaidforlife.org.uk/febrile-convulsions-what-are-they-and-what-should-you-do/.