By 9 months it's already gone up to 104-105 to worry unless the fever spike has been sudden or there are other things going on like no wet diapers in 6-8 hours or other symptoms that are worrisome like a sudden rash or non-responsive behaviors.
If the fever persists you can go back and forth with ibuprofen and acetaminophen every 3 hours. Otherwise you can give either ibuprofen every 6 hours or acetaminophen every 4 hours.