Yesterday night my daughter had a fever. She took ibuprofen, it seemed…

Yesterday night my daughter had a fever. She took ibuprofen, it seemed to lower it and after 3-4 hours the temperature went up again, and so on until now. I'm trying to bring it down when it rises again. Should I put candles in? I think maybe this is because of her teeth or something blew somewhere? How long do they get sick with tooth pain? How does this even happen?