Home > Infectious Disease > What Causes Fever? Get the Flash Player to see this player. Rate: (Click the stars to rate) Published on Oct 05, 2008 by LBernstein, Views: 4033 Fever is the bodies response raising the core temperature usually to help fight off infection, although there are also other causes of fever. Dr. Lisa Bernstein from Emory University, discusses what fever is, and when you should be concerned about fever. Any fever above 98.6 is abnormal. A fever above 102 in a child is worrisome and you should call your pediatrician.