Anybody know what this might be

It’s raised and feels hot to the touch wasn’t like that last night

It doesn’t seem to bother him

I noticed it after he had woken up from his nap yesterday as it wasn’t there before I would’ve noticed it there because I changed him into pajamas

I’m not sure where he could have gotten it we were at my grandparents yesterday we didn’t do much all he did was play with his toys

He does like to sleep on his tummy with his butt in the air and he does move a lot in his sleep so I’m thinking he got a burn from the couch

I waited till today to see if it would go away or get better but it didn’t so I might take him somewhere to get it checked out just incase it could be a bug bite like spider or something (his doctor is closed today as it’s a Sunday)

He’s a year old for anyone wondering