Yes, I have this problem. I get nerve blocks about every 2 weeks to control my RSD. My Pain Mgt. Dr. always takes the temperature of my good arm and the RSD arm before each nerve block. The difference is between 5 - as much as 11 degrees. Then after the nerve block it is usually only 1 -2 degrees difference. She described in medical terms why this is (over my head) but basically it involves circulation and how nerve condution in the brain controls this.