Calibration of a camera have various applications in computer vision. This process is particularly challenging with a thermal camera instead of a standard color one. A calibration target with two layers of different thermal emissivity is commonly used but reflects appear and degrade the corner extraction of the chessboard. While traditional and commonly used methods heat the target chessboard, we cool it down that inverts the distribution of emission of the two layers. The reflects on the reflective layer enhance the contrast instead of decreasing it. Experiments on various configurations and orientations demonstrate the superiority of the proposed method.