Hi - I just read this today - I have been very slow in comingin here period and I have the same problem - I have been fighting with this for years.

First I heard the never ending "oh those are Hot Flashes" and now that I am way past that age I just get a shrug - no one has ever figured it out -
I read one article that said it is inherited and Belladonna (?) in small doses helps - I have not tried it because I think I am on enough medications and of course those could help this problem.
The Pharmacist says it could be any of the meds or none - there is no way to tell - so I sleep with a towel under my head - and carry a small one with me - try to keep my hair off my neck since that seems to be the worst area - and just go on. Don't know what else to to - I do know how miserable it is though.

Morri