New RSD is an inflammatory situation. I was just looking at this on some web page. I know the Dutch researchers state take as much NAC supplement that you can handle to bowel tolerance.
Yes, the cold is bad for RSD due to the vasil constriction. I started my RSD in my right arm back in 1984. If you can get to the right treatment quickly before it spreads is the trick. Early RSD is curable. Anaprox ( name brand) is really good for inflammation. Keep the limb warm. buy or make a something that can be heated in the microwave to keep the limb warm. Bucky had booties and mittons made with buckwheat. They are put in the microwave for 1 minute and put on the limb, and it will break the cycle of the vasil constriction. Also regular granulated sugar in warm water, soaking the limb ( reheating the water) will break the pain & vasil constriction cycle.
There is also a sinus block that an ear nose doc can show you - to use a 1 sided long 'cutip' to go down your nose into your sinus to acess the nerve bundle. Using 2% liquid lidocaine, letting the cutip rest on that nerve bundle for at least 10 minutes. It works as an upper body nerve block. You can do it several times each day to shut down the sympathetic/autonomic nervous system firing...