Over the last decades, our understanding of the relationship between thermoregulation, performance and fatigue has changed dramatically. New advances in technology and methodology permitted the study of rising and decreasing body temperature on metabolism and provided insights into the role the nervous system plays in determining human performance under thermally stressful situations. Further analysis of previous research has been necessary in addition to considering theories derived from complimentary areas of research such as evolutionary biology, anthropology and cellular and molecular biology. This publication provides different interpretations of recent research for a better understanding of the limitations of thermoregulation. In particular, it presents evidence for the human's ability to anticipate thermal limits and adjust their performance accordingly so that cellular homeostasis is preserved. Further, the book is featuring the inclusion of the effect of reduced body temperature on muscular performance and endurance which today is a popular method for providing avenues of reduced thermal strain and recovery from exercise. This publication will be an essential read for those working in thermal medicine, exercise physiology and human performance.