The first fever a baby or an infant has is often scary for parents. Most fevers are harmless and are caused by a mild infection. Overdressing a child may even cause a rise in temperature.
Regardless, you should report any fever in a newborn that is higher than 100.4 °F, taken rectally, to the child's doctor.
Fever is an important part of the body's defense against infection. Many older infants develop high fevers with even minor illnesses.
Febrile seizures do occur in some children and can be scary to parents. However, most febrile seizures are over quickly. These seizures do not mean your child has epilepsy, and do not cause any lasting harm.