The surface heat flux and its distribution in space and time is an important parameter in numerous engineering problems. In this content, we present a method for estimating transient, multidimensional heat flux distributions by measuring the temperature distribution on the surface of an object and by applying inverse techniques. The proposed method can be used for transient heat transfer processes and particularly for heat transfer problems where lateral heat conduction along the surface plays a significant role. The method is based on two-dimensional sensitivity matrices, which have been expanded to a three-dimensional sensitivity approach. Thereby, the profile of the heat flux does not have to be known beforehand. As the introduced method is applied on the surface of the investigated objects, the frequent problem with instabilities due to the ill-posedness of the inverse problem is significantly reduced and no further stabilization procedures are required. The method improves available methods based on one-dimensional heat conduction, due to the consideration of three-dimensional heat conduction. (C) 2016 Elsevier Ltd. All rights reserved.