Suggest Remedy For Persistent Vomiting And Diarrhea

My 3 year old son has been throwing up and has had diarrhea for about 7 hours now. He can't keep anything down. He's been drinking water and Gatorade but everytime he takes a drink he throws it up right away. He does not have a fever. Do you think I need to take him to the er since the doctors are closed now?