The physiology of man is a complex subject. Unfortunately the regulation of temperature in the human body is not always well explained in textbooks. Many conference proceedings on the subject have been produced that give excellent detail on research topics. However, the subject matter is rarely presented as a composite whole. New technology has broadened the scope of methods available for studying body temperature. Thermography in particular has made it possible to record in real time the temperature distribution of large areas of the body surface. Modem image processing methods permit dynamic studies to be carried out and detailed analyses made retrospectively-a tremendous advance over the complex and slow techniques formerly used by physiologists. Yet although the associa tion between disease and temperature is as old as medicine itself, beyond the implicit faith in the clinical mercury thermometer, other measuring techniques are finding a slow acceptance. This book is designed to put into perspective the critical factors that make up "body temperature. " Body temperature cannot be viewed as a static entity but rather must be seen as a dynamic process. An understanding of this phenomenon is important to all who use thermal imaging and measuring techniques in clinical medi cine. These methods have, in recent years, brought engineers, physi cists, technicians, and clinicians together. Inevitably, however, there v vi Preface are gaps and overlaps in technology and understanding.