I was diagnosed with mild Raynaud's many years ago, but I don't think it is related. In the past, this symptom has waked me up. I go to the tub and run cold water over my feet. Then I come back to bed and rub hand lotion on my feet and hands. The evaporative cooling effect feels nice.
I think I know what I was doing to cause this (described in my 27 Oct 2011 post below). I've stopped it, and, so far so good. ******** UPDATE: THIS IS POSSIBLY RELATED TO MELATONIN - SEE MY POST BELOW OF 5 MAY 2013. ******** UPDATE: Feb 2018: I no longer believe Melatonin is causing this. I'm back on it for the past three years, taking 1.5 mg at bedtime, and my hot hands and feet have thankfully all but disappeared. I cannot explain what I changed to stop this problem, other than stopping social smoking at the bars.