With the death of Evelyn Satinoff, psychology has lost not only a preeminent researcher and teacher but also a real character. As a professor and pioneer in the field of thermoregulation, she could be intimidating; as a friend, she was warm and loving. Evelyn was born in Brooklyn, New York, on April 25, 1937. She graduated from Brooklyn College in 1958 and received a doctorate from the University of Pennsylvania in 1963. She then remained there, first as a National Institutes of Health postdoctoral fellow and then as a research associate. Much of her early research focused on the neural control of behavioral thermoregulation. More than anyone she is credited with demonstrating that behavioral thermoregulation can be as important in maintaining body temperature as are physiological mechanisms. Evelyn was active in several professional organizations, particularly APA Division 6 (now Behavioral Neuroscience and Comparative Psychology). She was diagnosed with lung cancer in 2006 and after a valiant fight, she lost the battle, dying in her beloved Manhattan on January 29, 2008. Love her or hate her, Evelyn was unforgettable, and the world is poorer for her passing.