Good evening. Has anyone's kids had a fever in their teeth? We have a …

Good evening. Has anyone's kids had a fever in their teeth? We have a river of saliva. The temperature was 37.5 all night and morning was fine, but during the day it was all good, there was no temperature. Now it seems to be rising again in the evening. It's 37 now. The baby is active, eats, runs around. A little bit fussy. But he behaves as usual even with a fever. He only slept restlessly at night. I'm even confused, do we need to see a doctor under such circumstances?