The Ice Cream Pinch
I have no idea why I get a headache when I eat ice cream too fast. I guess I could avoid it if I'd eat more slowly. But when I get the "ice cream headache" I can get it to go away by pressing my pointing finger just in front of my ear (in the little dip there) and press up and in with my thumb just under and behind my ear, almost pinching my ear with the finger and thumb.
Occasionally I begin to see "sparkly twinkles" in my lower right field of vision which gradually expand up and around to the left, obscuring most of my vision. About 20 minutes after the "twinkles" start, they go away and I end up with a headache. One of the first times this rather frightening thing happened I went to an eye doctor. He didn't say that I'd had a migraine, but he did ask me if anyone in my family has migraines. (No one does.) So I've just assumed that this may be some sort of migraine.
I've tried the "ice cream pinch" the last several times that I've had an episode. The first time, the "twinkles" went right away and I got no headache. This hasn't happened since, but I've not developed the headache which normally came after the "twinkles" went away since I've been doing it. I don't know if it's necessary to do the pinch all the time that the "twinkles" are visible -- the pressure can get to be a bit unpleasant after 15 or 20 minutes. So I pinch for a while, let up for a while, then do it again.