Hi, If I were your treating Doctor for this case of vomiting, I would come up with three possibilities, these include: The first possibility is of infection. Diagnosis can be confirmed by asking question: Did you wash hands before meal? . Try giving ORS, Charcoal 2 tablets for absorption of toxins. It also might help to avoid eating or drinking tea for two hours. To help control the stomach acid, one should takes rice soup,boiled mashed potato;avoid to eat chocolate or spicy or greasy foods.In this case headache can be symptom of intoxication. The second possibility is of dehydration as it may lead to increasing leel of uric acid in the blood which is worse when child don t drink water. Pancreatic enzymes like serum amylase and lipase,liver test,stool culture should be measured to rule out any pancreatic cause. The last possibility is of heat wave which may cause hypotonia. For this purpose you need to check BP. I suggest you to consult a paediatrician and keep her hydrated with plenty of water. For headache you can give Paracetamol or Ibuprofen. Hope this answers your question. If you have additional questions or follow up questions then please do not hesitate in writing to us. I will be happy to answer your questions. Wishing you and your son good health.