I got fever in 3 hours raised from 37.5-to 38.2, 38.5 with chills in whole body even i was covered and the ambient was normal temperature. i have little headache, no runny nose, sore throat... thank you for reading and answering.

Can see doctor: Most people have a headache at some time, such as from colds and flus, lack of sleep, too much driving, long hours on the computer, stress at work, etc... Headache with fever may be an infection, such as the flu, other viruses (some of which can cause viral meningitis), bacteria, or rarely other germs. A bad or increasing headache, recurrent or weird headache, etc., should be examined.