HELP!!! FTM-baby's temp reading 101.4

J
NO other symptoms. The little boy I nanny had a low grade fever with no other symptoms a few days ago which I didnt go in that day just in case but it never turned into anything. Now baby's temp is higher than it's every been but he has NO other symptoms, is his normal happy self. I can't think of anything it could be! What do I do?! he is 5&1/2 months. I'm a FTM