The effects on the heads of human of the electromagnetic waves produced by mobile antenna are presented in this paper. The interactions between electromagnetic energy and the human head are modelled using a COMSOL simulation and the distributions of the produced electric field and resultant temperature inside the human head are obtained. A planar Inverted-F antenna (PIFA) was adopted in this modelling. Three levels of transmitted power (0.6, 1, and 1.5 Watt) were applied in the simulation to determine any increases in temperature in the brain due to microwave radiation from the mobile antenna.