Hello, I have a 16 year old daughter who is usually in very good health. She started with a fever early this AM about 4:00 fever was 100.9. She threw up twice. Gave tylonal then, and every 6 hours afterwards, No more vomiting but fever has moved from low grade to medium grade right before it's time for the next tylonal. Fever is now 101.4. Is it very concerning that fever is getting higher? Could this be the stomach flu? Thank you very much.