non medical- if it's a run of the mill headache, pinch the skin between your thumb in index finger as hard as you can for as long as you can stand it. (acupressure point)

It it is sinus related, place your thumb and index finger on the bridge of your nose and press in, then push against the roof of your mouth with your tongue, directly behind your front teeth. repeat 5 or 6 times until you begin to feel your sinuses drain.

good luck.