What Causs Headache, Vomitting And Tiredness?

My 12 year old son has a high fever, headache, vomiting and sleepiness. Started this morning with a fever of 102 F tympanic and headache but he fell asleep . Then this afternoon he awoke moaning and holding his head. I again took his temp and it was 104.4 F. then vomited. Gave him another Advil and drink and he went back to sleep. Checked temp a little later and it was down to about 102. He slept again and woke up about 9:00. Moaning again and a fever back up to 104.4! I just gave him 2 Advil and cold compresses. Checked him again and his fever is now down to 100.9. Should I take him to the E.R.? Or wait till tomorrow and take him to a clinic.