In this paper, the authors propose a thermal modeling of a fuel cell. It has been validated on a 150 W power PEMFC. The thermal modeling uses a network of 172 nodes. It takes into account conduction and convection heat fluxes but also mass transfers due to electrochemical reaction. This thermal model is reduced to a global model describing electrical behavior and takes into account temperature regulation of the water cooling system. Matlab-Simulink software has been used. Dirichlet boundary conditions are obtained thanks to an SW infrared camera.