thanks for posting your query to healh care magic. there are so mny causes for rise in temperaure .you dont need to worry just consult to physician and investigated properly .you should undergo complee blood count (CBC) ananlysis , it will guide you weaher fever is due to infectin or due to anaemia or any other cause .and dont be think about HIV as it is not a acute illness it develop after a prologed course . you need to tell me about your age ,profession . sexual history, family history of any illness etc. then I would be able to guide you further . thanks .