Hi Geronimo and welcome to neurotalk. I'm sorry you have this disorder. I have both hot and cold rsd.The sympathetic nervous system controls temperature, circulation, immune system, involuntary organs like the heart, lungs, kidneys. The sympathetic nervous system can cause high blood pressure and the para sympathetic nervous system can cause low blood pressure, which if gets too low can pass out, which happened to me. We can be burning up or freezing cold. The skin can be pink to reddish blue -hot or ice cold. There is a website with a lot of information from a Florida Dr. He is retired, but has his website up It's rsd.rx Go to puzzles and there are 146 puzzles or questions and his answers.
RSD can also cause problems for internal organs. I've had this 15 years, full body or generalized now and internal organs. It can effect the eyes, ears, skin conditions, lesions, teeth,mouth. This website explains this and the hot and cold question you have.
Hope the best for you, your friend,, loretta