http://www.cliving.org/stressthermometer.htm
How Temperature Relates To Stress Under stress muscles tense and blood
flow is restricted to the main body and shut down from the hands and feet.
Stress Level Rule - Warm Hands Relaxed, Cold Hands Tense. Hand/foot
temperature ranges over 40 degrees from a low of 60 degrees to as high as
99 degrees F. Changes of 5 degrees or more can take place in seconds.