Hi Barb,
When I am in the sun, I mean with the sun directly on my head, it burns and hurts. Even for hours later unless I go in and wash my hair and run cool water on it.
I may put an ice pack on it for a short time, on and off. It is not sunburn, it is just my head can't stand the heat of direct sun. I feel like it heats my brain, odd feeling. Then it goes away, unless I do it again.
I have always wear a hat in the sun, when I know I will be exposed. Mostly a baseball-girlie-type-hat around the neighborhood or a hat that is currently in style. Whimsical even.

I don't know if that will help you, just what happens to me.
What did your Neuro say?