A sealing assembly for a dock leveler comprises two side restraints mounted on a loading dock along respective left and right sides of the vertical face of the dock leveler. A bottom restraint is mounted on the loading dock below the vertical face of the dock leveler. A mat is removably insertable between the side restraints. The mat is sized to allow left and right edges of the mat to engage the side restraints when inserted therebetween. The mat is foldable to define a vertical portion that covers the vertical face of the dock leveler and a horizontal portion that covers at least part of the horizontal face of the dock leveler. The mat substantially restricts airflow into and out of the loading dock through the gaps when the vertical portion of the mat is inserted between the side restraints such that a bottom edge of the vertical portion of the mat engages the bottom restraint, and the loading dock door closes atop of the horizontal portion of the mat.