Febrile convulsion is a fit, or seizure, associated with an infection (usually viral) causing a rapidly rising temperature. They are distinct from the attacks, called rigors, which can affect any of us as a result of fever: with rigors, there is uncontrollable shaking without loss of consciousness; with a febrile convulsion there is loss of consciousness and associated tonic-clonic (the muscle tone increases, and there is repetitive flexion and extension) movements of the limbs. They usually affect children under the age of three, but can occur up to the age of six. There is often a family history, and they may be recurrent in susceptible children. While most febrile convulsions are self-limiting and imply no greater risk of the development of epilepsy in later life, if they are prolonged (lasting longer than 30 minutes), or recurrent, or occur in an infant with a first-degree relative with epilepsy, then the risk may be increased. With a first attack, it is important to exclude serious bacterial infection such as meningitis. Thereafter prevention is important; the infant with a fever and a history of febrile convulsion should be cooled by tepid sponging and the use of both paracetamol and, if necessary, ibuprofen. Convulsions lasting longer than 5 minutes should be terminated using rectal diazepam.