My 9 month old vomited a lot about half an hour ago. he does not have a fever and he does not have a runny stomach. he does not want to drink something and fell asleep now. do i need to take him to the er or just watch him. worried about dehydration.

Basic issues: Vomiting is often the 1st symptom of a food reaction or stomach virus & may precede fever,cramps & diarrhea by many hours. A kid that age is not suddenly dehydrated. If they retain enough fluids to pee every 6-8 hrs they are hydrated. Ice chips & sips of fluid from a cup/bottle can help them maintain fluid balance. Go in if you are spooked, but many of these pass & self heal.