3 year old goes under anesthesia for dental work

My 3 year old underwent dental work under general anesthesia at a pediatric hospital.  He seems to be doing fine today although he has a slight fever....I wonder how long this is normal to go on...running a fever. He has a little upset stomach today too and I wonder if this is from the anesthesia...His face also seems a little red and I am not sure if this is from the trauma or from where they had tape stuck to his face to hold the breathing tube.  He has not complained much of his mouth hurting. He had his four front teeth pulled, eight crowns and four root canals. Just wondering if anyone out there has had similar situation. He has a great appetite and is drinking great