Stress may save your life if you're being chased by a tiger. But if you're stuck in traffic, it may be more likely to make you sick. This hour, a long hard look at the body's system for getting out of trouble.

Stanford University neurologist (and part-time "baboonologist") Dr. Robert Sapolsky takes us through what happens on our insides when we stand in the wrong line at the supermarket, and offers a few coping strategies: gnawing on wood, beating the crap out of somebody, and having friends. Plus: the story of a singer who lost her voice, and an author stuck in a body that never grew up.