Book excerpt: This publication focuses on the medical management of individuals involved in radiation emergencies, especially those who have been exposed to high doses of ionizing radiation. Its primary objective is to provide practical information, to be used for treatment decisions by medical personnel during a radiation emergency. It also addresses general and specific measures for the medical management of individuals who have been internally contaminated with radionuclides. This publication is complementary to other publications developed by the IAEA in the medical area of radiation emergencies.