A medical data processing method, performed by a computer , for tracking at least a part of the surface of the body of a patient (P), comprising the steps of: - measuring, at a first point in time, first locations of a plurality of points on the surface of the body by 1) acquiring at least two two-dimensional image datasets, wherein each two-dimensional image dataset represents a thermographic two-dimensional image of at least a part of the surface which comprises the plurality of points, and wherein the two-dimensional images are taken from different and known viewing directions, 2) determining the pixels in the two-dimensional image datasets which show said plurality of points on the surface of the body involving assigning a descriptor to each one out of the plurality of points on the surface of the body of the patient (P), the descriptor describing the thermal signature of the corresponding point and the area surrounding this point, and 3) calculating the spatial location of the plurality of points from the locations of the determined pixels in the two-dimensional image datasets and the viewing directions of the two-dimensional images; - measuring, at a second point in time which is later than the first point in time, second locations of the plurality of points in the same manner as the first locations; and - calculating a movement of at least the part of the surface of the body from the difference between the first locations and the second locations. - measuring, at a first point in time, first locations of a plurality of points on the surface of the body by 1) acquiring at least two two-dimensional image datasets, wherein each two-dimensional image dataset represents a thermographic two-dimensional image of at least a part of the surface which comprises the plurality of points, and wherein the two-dimensional images are taken from different and known viewing directions, 2) determining the pixels in the two-dimensional image datasets which show said plurality of points on the surface of the body involving assigning a descriptor to each one out of the plurality of points on the surface of the body of the patient (P), the descriptor describing the thermal signature of the corresponding point and the area surrounding this point, and 3) calculating the spatial location of the plurality of points from the locations of the determined pixels in the two-dimensional image datasets and the viewing directions of the two-dimensional images; 1) acquiring at least two two-dimensional image datasets, wherein each two-dimensional image dataset represents a thermographic two-dimensional image of at least a part of the surface which comprises the plurality of points, and wherein the two-dimensional images are taken from different and known viewing directions, 2) determining the pixels in the two-dimensional image datasets which show said plurality of points on the surface of the body involving assigning a descriptor to each one out of the plurality of points on the surface of the body of the patient (P), the descriptor describing the thermal signature of the corresponding point and the area surrounding this point, and 3) calculating the spatial location of the plurality of points from the locations of the determined pixels in the two-dimensional image datasets and the viewing directions of the two-dimensional images; - measuring, at a second point in time which is later than the first point in time, second locations of the plurality of points in the same manner as the first locations; and - calculating a movement of at least the part of the surface of the body from the difference between the first locations and the second locations. <EOS>