If you are an adult with a fever over 104 F (40 C), call your healthcare provider. If it is over 105 F (40.5 C), go to your nearest emergency room. For a newborn, a fever of 100.4 F (38 C) requires ...

A fever is typically harmless and can occur when the body fights an infection, such as the flu. Persistent high fevers or additional symptoms, such as abdominal pain or difficulty breathing, may ...