Fever is a symptom of an underlying illness, not an illness itself.
Fever is the normal and healthy response of the body to an infection.
An oral temperature of 100.4 F or higher means your child has a fever. A higher fever does not always mean a sicker child. Each child reacts individually to fever-producing illnesses. It's really up to you. In most cases, a ball park figure is all you need when your child has a fever.