What can we learn from extremes? On this episode, we’ll meet athletes who are ready to risk their lives to shed pounds quickly, med students who leave their classrooms to sleep in the freezing rain, anti-vaccine citizens marching in Washington, a bird researcher on a crusade against free-roaming house cats, a little boy so sick with food allergies that even a tiny cracker poses a threat, and a woman who’s giving up creating trash for a month – and maybe for life.