I wish I had an answer for this. There is the whole injured nerve that sprouted extra adrenoceptors that react to cold and cause pain and vasoconstriction, blah, blah, blah answer.....but I am just not sure.

The top of my injured foot is often cold. I thought it warmed after ketamine but yesterday it was showing a whopping 7 degree difference again. It didn't even hurt! And strangely it is not the area that took the big hit nerve wise.

Alpha blockers might help with both circulation and pain. Topical clonidine might be an option too.

I'm glad you're sleeping a little better. That's a start!

Let us know what you find out.