This work focuses on the thermal behavior of an anode-supported planar solid oxide fuel cell (SOFC) running under different operating conditions and fuel compositions. A seal-less in-house ceramic housing was specifically designed and built to test the fuel cells and characterize their electrical performance as well as the thermal field established across the anode surface area. The housing design we used allowed us to measure the temperature in 8 different positions along the cell radius. Our experimental sessions were thus dedicated to observe the electrochemical performance and the established temperature field across the SOFC active area under several operating conditions, obtained by varying the inlet fuel composition, the fuel utilization factor and the current density, respectively. The fuel composition was varied by feeding the SOFC with hydrogen fuel, diluted-hydrogen and finally methane, in a direct internal steam reforming configuration. During each experiment, the temperature field across the cell was measured while varying the current density: results were compared together among the different fuel compositions used, showing a consistent thermal gradient established even with relatively small-sized cells. The paper also outlines key issues in the development of ceramic housings with multi-measurement capability. (C) 2011 Elsevier B.V. All rights reserved.