I don't know of any studies... but I can tell you that my physical therapist used ice on me and I thought I was on fire... I've never felt pain like that. Normally ice will hurt until the are goes cold numb... mine never did go numb...pain just kept going up.

When I told my doctor that's when I was diagnosed with RSD... well this and the other symptoms combined.

After the RSD diagnosis my PT put in the file to never use ice and through trial & error we found out I can't tolerate temperatures below 60 or over 80 without it causing a major flare.