In the present work, the effect of various heat sources, gas temperature and configuration on the temperature field within a Planar Solid Oxide Fuel Cell is studied (SOFC). In order to describe the thermal behavior within the SOFC during its operation the coupling of the mass and energy transport phenomena along with the electrochemistry is required. More precisely, the subject of the present analysis is the visualization of the temperature field and the location of the highest temperatures within an Electrolyte Supported Planar SOFC (ESP-SOFC) fed with hydrogen and air. The studied parameters are: i) the temperature values of the reactants and ii) the different types of the heat sources; due to the over potentials, the Joule effect and the water formation. The complex system of the governing equations is numerically solved with the finite differences method and the temperature field within each domain of the ESP-SOFC is calculated via a mathematical model implemented in FORTRAN language. The mathematical model predictions for the temperature gradient within the ESP-SOFC under the influence of the studied parameters are thoroughly discussed.