After 7:30 or so, he woke up again and asked to go to the bathroom. Then (unprompted) he asked for the blue basin because he had to "throw up." We figured he must have an upset stomach. A few moments after we gave him the basin, sure enough he threw up into it. We couldn't help but feel prideful of our son--as he spewed out his guts--who is not even 3 years old but has the presence of mind to request a basin to vomit in (contrast this with Paul's college drinking days...best left unsaid).
Sammy seems to be doing better now, he's still vomiting occasionally (each time he requests the basin). After a bath he seemed to perk up more.