Coldness was one of my very first symptoms (other than the pain) that I got. My leg would get ICE cold from my knee down (RSD in my ankle). So cold to the point where I would walk on tile and the tile would feel cold to my good foot and HOT to my RSD one. It was also one of the key symptoms that tipped off the doctor who diagnosed me that it was RSD.

Now (my RSD has spread to my entire upper body since then) I still get the coldness...but not as often. It typically only comes with bad flares...which can be caused if I am using my RSD areas too much or they can come out of no where.

As always...you should definitely discuss this with your doctor to make sure there is nothing else causing the issue. You wouldn't want a circulation problem to go undiagnosed just because RSD COULD be the cause.