Sudden fever of around 100. 9. Age 11 ye

My son of 11 years suddenly got fever today around 100.9. Gave Dolo 650. Fever reduced slowly to around 100 after 2 hours. Applied wet cloth on forehead and wet cloth on body under fan. After 3 hrs reduced below 100. Actually fever I felt in the afternoon itself when he touched me around 3pm. But we ignored. Later at 9 pm he suddenly started coughing. So the story started. But after 3-4 hours as I told. Fever went down. Important to note cough went down and down as fever reduced. Now he is NOT coughing. But still I feel his body is hot. Question is in how many hours gap I can give Dolo ? Every 4 hours if fever is there? Say around 100? Anyway I will go for consultation. Just want to know if someone can answer tonight