The present disclosure provides for a coated flexible open-cell polyurethane foam structure. The coated flexible open-cell polyurethane foam structure includes a flexible open-cell polyurethane foam having a first major surface and a second major surface opposite the first major surface. The coated flexible open-cell polyurethane foam structure further includes a flexible heat conductive material covering 30 to 90 percent (cov., expressed in %) of a surface area of the first major surface of the flexible open-cell polyurethane foam in a predefined shape to provide one or more gaps exposing the flexible open-cell polyurethane foam between defined edges of the flexible heat conductive material, where each gap of the one or more gaps has a gap width according to Formula I: gap width (mm)≤−0.196×cov. (%)+20.6 (Formula I) where a total surface area of the one or more gaps provides 70 to 10 percent of the surface area of the first major surface of the flexible open-cell polyurethane foam.