Our whole family got sick at the end of our vacation. DD2 threw up a couple of times, then 24 hours later I started vomiting/diarhea, 12 hours later DH, the same, DD1 go it last very cranky and tired, slept majority of the trip home 20 hours, but was fine once we got home. She never had diahrea and threw up only a couple of times when we were in the car on the way home. We had no thermometer with us so we don't know what our temp was. After we got home it dispursed among the rest of the family. Not everyone puked and not everyone ran a fever, so the symptoms varied.
You have to realize, if he was up all night he has to make that sleep up somewhere aka the trip home. Is he drinking just fine? If he is drinking and not vomiting I wouldn't be too worried, so long as the sleep pattern returns to normal over the next 24 hours. You might find he it up all night again, hope thats the case. But trust your gut, if you really think something is wrong do what you need to do.