8 yr old seemed to develop fever quickly 102 complaining back of his head hurts.theres a small lump under his jaw?

Fever: Fever can cause headaches in children.the lump under you child's jaw may be a swollen gland. Take you child to the doctor to determine the cause of his fever.A throat culture would be a good idea in view of his swollen gland unde his chin

See doctor: The fever and lump under the jaw (lymph node) suggest an infection of the throat. I would have him checked by his doctor as soon as you can.