This volume essentially deals with the electromagnetic and acoustic methods of external hyperthermia - a type of thermotherapy by which heat is supplied to tumor tissue in an external, noninvasive manner. As the development of equipment capable of producing and monitoring safe, effective, and predictable hyperthermia treatment represents a major challenge, all biophysical, biological, and technological aspects of the different heating techniques are discussed comprehensively. Particular emphasis is laid upon the problems involved in hyperthermic heating of deep-seated tumors, in particular concerning the control of power deposition pattern, and the technological advances in both radiofrequency and microwave applicators and ultrasound transducers. Methods and standards for the physical evaluation and quality assurance of hyperthermia equipment are described extensively.