An experimental study quantifying the thermal behavior of a mechanical seal is performed. Temperature measurements are obtained using embedded thermocouples within the stator at different locations, and the tests are carried out at different sealed fluid pressures and rotary shaft speeds. Furthermore, an inverse method is used to calculate the heat transfer from the measured local temperatures. The Nusselt number is calculated along the wetted surface as a function of operating conditions; the obtained values are discussed in comparison to previous works. Our results demonstrate that the amplitude of the thermal effects is highly dependent on the operating conditions. The temperature rise being increased by 600% when the rotating speed is raised from 1000 to 6000 rpm and the fluid pressure from 1 to 5 MPa. Moreover, the temperature can vary by several degrees when the distance from the wetted diameter (cooled by convection) and the friction face (heat source) is varied from less than 2 mm.