The second edition of the Radiofrequency Radiation Dosimetry Handbook extends the data contained in the first edition, which was published by the United States Air Force School of Aerospace Medicine in September 1976 [Johnson et al., 1976]. Several additional techniques have been used to extend the frequency range over which the specific absorption rate or mass-normalized rate of energy absorption (SAR) is calculated for models of human beings and animals, which results in useful theoretical data over the frequency range 10 kHz to 100 GHz. Some information is also given about ground-plane effects, experimental data found in the literature, and thermal effects of irradiation.