A febrile seizure is a seizure which occurs in an infant or a small (generally younger than 5) child due to fever. This is not so much due to the height of the fever but the speed with which the child's temperture rises. What happens is that the child's temperature rises too fast for the brain to adjust to it. Increased temperature causes higher metabolic rate and more electrical discharges in the brain. In little ones, whose nervous system is still developing, and who haven't yet pruned all their excess neurons, this can lead to the disordered electrical activity that we call a seizure.
While a febrile seizure is tremendously frightening to the parents, it is self-limiting and harmless. There is no correlation between febrile seizures and brain damage, or febrile seizures and the development of epilepsy. While any first seizure should be evaluated by a physician, some children simply have a tendency to have febrile seizures. In these children it is not necessary to take them to the emergency room every time they run a temperature and have a febrile seizure. However, having two febrile seizures in the course of the same illness is associated with a somewhat higher chance of a serious infection being present, and does warrant a visit to the child's pediatrician.
As an ER nurse, what we will do if your child comes to the ER with a first-time febrile seizure is mainly to take its temperature as well as a good history. We will ask when the last time was that your child had either Tylenol (acetaminophen) or Motrin (ibuprofen), and give one or both. Depending on the temperature, other symptoms, and history, we may do lab work (mainly a CBC and a urinalysis) or a CT scan. We may not, and simply watch the child to see if the temperature drops appropriately and whether another seizure occurs. Your child will most likely stay in the ER for a few hours, then go home.
With a second seizure in the same illness, your child will probably get a more extensive work-up, possibly involving a lumbar puncture and blood cultures to rule out infections in the nervous system and blood stream. The child might be admitted overnight for closer observation, or it might be sent home depending on the lab results.
In a child with a previous history of febrile seizures, the course of action is almost always administration of antipyretics in the emergency room, observation until the temperature is dropping, then discharge. Especially if you have poor or no health insurance, you might want to consider not visiting the ER in this situation.
My work as an Emergency Room RN
National Institute of Neurological Disorders and Stroke fact sheet