Despite the brain’s importance, it can’t function without a complex system of sensors less than one-twentieth of an inch beneath the skin. This program guides viewers through the various gateways to the body’s central nervous system—our sense of touch, our reactions to heat and cold, and our ability to feel pain. Case studies feature a helicopter pilot whose fine-tuned steering abilities saved the lives of two stranded swimmers; a dentist who regularly performs root canals with the help of hypnosis, not anesthesia; a man bitten by a deadly spider and saved by his sensitivity to pain; and more. Innovative 3-D animation reveals the anatomy of physical trauma—from intense heat to devastating leg fractures—and the body’s ability to quickly and effectively react. A Discovery Channel Production. Part 2 of the series Human Body: Pushing the Limits. (43 minutes)