A high fever is when the body temperature rises above 103 F in an adult (or above 101 F in a child). A fever this high may indicate the presence of a serious infection that has triggered your immune system.
When such a fever occurs, particularly if it doesn’t go down within a day, contact a doctor. Also, any person of any age who sustains a fever for several days, even if it’s lower than the high fever range, could have an infection and should contact a physician.
Keyword: high fever