In typical JET shots the NBI heating leads to a plasma with the ion temperature (Ti) equal or higher than the electron temperature (Te). With the prospect of ignited plasmas an interest of hot-electron scenarios has emerged, since the a-particles created as a by-product of the fusion reaction mainly heats the electrons. A better understanding of the transport properties for Te>Ti is thus needed. The plasma response to different heating schemes is also related to the stiffness of the plasma. A stiff plasma exhibits a critical steepness of its temperature profiles and whenever the applied heating tries to push the temperature profiles beyond this critical value, the plasma responds by amplifying the heat diffusivities. As a consequence the profiles remain unchanged. From a theoretical view point, the Weiland model predicts that this critical steepness and the magnitude of the diffusivities depend on the temperature ratio Te/Ti. To validate this claim and gain an improved knowledge of plasma transport properties it is important to further clarify the plasma response to increasing heating, ion or electron.