An apparatus for cooling tissue or a fluid for an elongate medical device comprising an elongate shaft extending along a longitudinal axis and comprising a shaft proximal end and a shaft distal end； a support structure located at the shaft distal end, where the support structure is expandable from a contracted state to an expanded state, and a plurality of thermoelectric elements, wherein the thermoelectric elements are located on the support structure. A medical device comprising a first catheter end shape, a second catheter end shape located distally with respect to the first catheter end shape, a support structure that extends between the first and the second catheter end shape, and a plurality of thermoelectric elements. A system for cooling a tissue or a fluid for an elongate medical device, comprising a plurality of thermoelectric elements, a thermocouple, an electronic control unit (ECU).
