The temperature distribution inside a lossy sphere resulting from the absorption of microwave energy was approximated by successive numerical iterations. of the thermal energy equation. Heat transfer within the sphere by conduction was considered. In the model energy was not dissipated by convection but was contained in the sphere for over 200 seconds. Exposure of a 5-cm sphere to 3,000 MHz at 30 mW/cm2 for 200 seconds was calculated to produce a temperature rise of 0.56 degrees C near the front surface.