What Causes High Fever Along With Sore Throat In A Toddler?

Hello, My son is 2 years and 8 months old. Since last 3 days he is having fever about 102 C and 103 C. We took him to the paediatric, and diagonised sore throat and climate change. Medicines given are clavam forte and Combiflam, along with entergermino and lanoz. Today is the second day of the course, but fever comes back, as soon as the effect of Combiflam subsides, that is in 5 to 6 hours. We are sponging body/forehead. Also trying to keep him well hydrated. During the period when he has no fever he is active and playful. Please let us know if any other measures are to be taken.