Inverse Heat Transfer Problems (IHTP) rely on temperature andlor heat flux measurements for the estimation of unknown quantities appearing in the analysis of physical problems in thermal engineering. As an example, inverse problems dealing with heat conduction have been generally associated with the estimation of an unknown boundary heat flux, by using temperature measurements taken below the boundary surface. Therefore, while in the classical direct heat conduction problem the cause (boundaq heat flux) is given and the effect (temperature field in the body) is determined, the inverse problem involves the estimation of the cause f?om the knowledge of the effect. An advantage of IHTP is that it enables a much closer collaboration between experimental and theoretical researchers, in order to obtain the maximum of information regarding the physical problem under study.