In this work, a steady-state three-dimensional model is employed to investigate the heat transfer phenomena in a Planar Solid Oxide Fuel Cell (P-SOFC) and determine the current density impact on the overheating of this fuel cell type. The thermoelectric characteristics of various components of the P-SOFC are provided from the standard materials: Ni-YSZ for the anode, YSZ for the electrolyte, La1-xSrxMnO3 for the cathode, and LaCrO3 for the interconnectors. The partial differential equations governing the heat transfer phenomena in the different cell parts are modelled using the finite difference method in a threedimensional environment. A program in FORTRAN language is locally developed for solving simultaneously the discretized heat conduction equation. The interest of this work is focused on determining the temperature profiles, fields, and distributions as well as evaluating and analysing the heat created by the current densities produced by the cell itself. The obtained results' analysis shows that for the considered geometric configuration, the P-SOFC components' heating is found to be proportional to the electric energy production.