Sick for Christmas!!!!

My poor baby is about to be 6 months old and he just became sick throughout the night and today on Christmas eve! 😥 I feel sooooo bad for him as he looks miserable. His temp has gradually been increasing and was 100.9 when I last checked. I just gave him a 2nd dose of infant Tylenol. At what temp should I really be concerned and take him in to an urgent care or ER???? TIA!

Pic of my little sickling after giving him a cool bath to help his temp.... 🤞🏼 the Tylenol helps!!! 😕