My five year old came home from school with a headache , very tired and a low fever (101). Later that day he puked a few times and had a hard time staying awake. He was fine the next day until early after noon when his fever went up again (102) , I got it down to 100 after Tylenol and a lukewarm bath. Now its almost 2:30 in the morning and his fever has spiked up to 103.9 with severe headache, nausea , chills, very lethargic and whole body aches. I gave him some more Tylenol, but what do I do if doesnt go down or spikes up again?