A device for cooling the skin tissue of a patient during a procedure using energy includes a mat-like structure, the mat-like structure having a bottom wall, a top wall and upstanding walls connecting the top wall and the bottom wall, the walls defining an enclosed volume; it also includes one or more electrodes positioned to protrude from the bottom wall and extend through the volume for connection to a source of energy; further, the volume defines a space for holding a cooling substance for cooling the one or more electrodes and the skin tissue during an energy-based procedure.