I need quick answer plz for 2 months shot

Jalinar

My two month baby took his Vaccination yesterday. I told them to give him Tylenol before the Vaccination and they did. They gave me Tylenol for six hours. I did not give him anything yesterday because his temp was normal. Today he started having fever so I gave him tylenol. My question should I give him tylenol every 6 hours or only when it is needed , I mean when he has fever?