Three days the child has been holding a temperature around 39. I'm sup…

Three days the child has been holding a temperature around 39. I'm suppressing it, lasts for 5-6 hours and then rises again. The doctor on the first day said red throat and prescribed interferon ointment. Today we had to call an ambulance, in the hospital they examined and said that if the temperature continues tomorrow, then antibiotics will be connected. I don't want to give antibiotics ((). How long can a fever last? We will definitely follow the doctor's prescriptions, but maybe someone could share their experience? Tomorrow I also plan to go see another private pediatrician.