Abstract: A cooling/heating pad of the present invention includes a pad portion, a water reservoir system and a heat exchanger, wherein the pad portion has the pad portion is a foldable, thin, double-layered bag and has a plurality of adhered regions formed by a hot-press or ultrasonic hot melting process to form the water channel between the adhered regions; the water reservoir system has a water reservoir and a water circulating pump, the water reservoir having a water inlet and a water outlet, the water inlet of the water reservoir connected to the water outlet of the water channel, and the water circulating pump moving the cooling water in the water reservoir from the water outlet of the water reservoir to the water inlet of the water channel; and the heat exchanger includes an electrical heating semiconductor chip, and a thermal conductor mounted on one side of the electrical heating semiconductor chip; wherein the thermal conductor directly contacts the cooling water in the water reservoir, or is mounted on a wat