How human beings have adapted to a wide range of stressful environments – extreme temperatures, solar radiation, high altitudes, and nutritional stress – has been the subject of much research in recent years by psychologists, biologists, and physical anthropologists. Here for the first time Dr. Frisancho presents in a single volume knowledge on human adaptation that has previously been widely scattered and highly specialized. He examines from physiological and anthropological perspectives the short- and long-term reactions of the human body to various environmental stresses. Based on research that has been done in the laboratory and from studies of native populations living in stressful environments, Dr. Frisancho discusses the effects of extreme heat and cold, solar radiation and the selective value of skin pigmentation, high altitude hypoxia, growth in high altitude populations, diseases related to life in high altitudes, diseases and effects of undernourishment, and disease and the westernization of diet. This work is a valuable and much needed introduction to the field of human adaptation.