When a child has vomiting and fever, there are two main reasons to consider: 1. Acute gastroenteritis due to inappropriate food or cold, which often requires the child to be given water and food fasting, as well as medication to protect the stomach, such as Famotidine. If the temperature of the fever is high, more than 38.5 degrees, the child needs to take ibuprofen suspension to reduce the fever. 2. It is likely that viral encephalitis has occurred, especially in the summer and autumn season is more frequent. The first thing to do is to take your child to the hospital to have an EEG checked. If the EEG is abnormal, it means that the possibility of viral encephalitis is very high and you need to take your child to the hospital for treatment quickly.