This paper describes a 3D thermal modeling by a nodes network model for two PEMFC of 150 and 500 W (respectively, 3 and 20 cells). Modeling are realized for each case for one cell before to be integrated on all the stack. Absolute temperatures of 112, air and water channels are used as Dirichlet conditions. Temperatures of external surfaces are obtained thanks to an infrared thermographic camera. Final external heat fluxes are deduced from the integrated model. (c) 2005 Elsevier B.V. All rights reserved.