A driver slams into the back of your car on a New York parkway, and you brace against the steering wheel, fracturing your wrist. The bone heals on schedule, but six weeks after the cast comes off, your hand is on fire. It's swollen, shiny, cold to the touch one hour and burning hot the next, and you can't stand the feeling of a shirt sleeve brushing against it. Your doctor says the words "complex regional pain syndrome," and now you're asking a hard question: what is a CRPS c