I know it very well. For many years, with the RSD in my left foot only, it was extremely hot. Not only did it feel like it was burning, but it was hot to the touch.
About a year and a half ago, the right foot all of a sudden it got cold. I mean, it feels like I have it in a freezer. I can't figure out how to get comfortable at night. (Heavy bankets or not?) I end up with one foot in bed and one out in the open.
I visited South Florida a short time ago and tried to keep my right foot directly in the hot sun as much as possible to warm it up, but it never felt anywhere close to a normal temperature.
I have to keep a heating pad under my desk at work and have it plugged in and on my right foot (the left one is still hot) to deal with the cold.
This is so wierd.

I don't wish this on anyone, but it is comforting to know I an not alone. Thanks for starting this thread.
Mike