This is a user-friendly monograph designed for medical students as well as graduate students and postdoctoral trainees in medicine and other health-related sciences who need a comprehensive overview of thermoregulation. It presents the bases of the modern concepts in thermal physiology and pathophysiology, bringing together the disciplines encompassed by this highly integrative field — physiology, anatomy, biophysics, molecular and cellular biology, pharmacology, neuroscience, pathology, medicine, and World Scientific Publishing Company — into a clear and concise form that can be read comfortably in a relatively short time. This text was conceived by the Commission on Thermal Physiology of the International Union of Physiological Sciences in response to its concern over the inadequate and outdated coverage of this topic in traditional textbooks. The membership of this Commission comprises international experts in each of the subfields of thermal physiology, with extensive research and teaching experience in their respective specialties. They are the authors of the chapters of this indispendable textbook.