A thermally stable proximity identification card is provided. The card includes a prelam layer that is a combination of polyvinyl chloride (PVC) and polycarbonate (PC). The PC provides for efficient heat distribution from electrical components held within the card. By evenly distributing heat, especially around metal components like antennas contained within the prelam, a thermal gradient is minimized between the inside of the card and the outside, thus reducing internal stresses of the identification card.