Energy is applied to a portion of a conducting body. A database is queried for a surgical procedure associated with a patient. The mass exchange of the cooling agent has a mass flow controller for the cooling agent which is output from the inner container; a controller of an instantaneous pressure in the internal container, and a delay circuit providing a pre-determined time-delay for mass flow controller operation. The sensor, the measuringregulatingcontrol unit and the memory unit form a compact unit or an independent field appliance. The rigid cover has a top wall and a skirt member projecting from a periphery of the top wall.