Topamax helps me with the heat and burn on the back of my neck and my head. I can immediately tell if I've missed a dose. I also take Cymbalta.

P.S. - I have "cold" RSD - the only burn I experience is in my neck and head. My extremities are often freezing cold, I wear 2 pairs of socks and gloves to bed and carry a heating pad and blanket everywhere I go in the house. So my symptoms might be the opposite of yours.

Good luck