A medical fluid probe includes a heat spreader structure that defines therein a fluid chamber that is in fluid communication with an external environment around the probe, and a thermal energy source in thermal communication with the heat spreader structure. The heat spreader structure functions as both temperature-control elements and structural elements. A variety of separate structure elements, such as the heat pipes, may combine to form the heat spreader structure. The thermal energy source may be used to maintain the temperature of the heat spreader structure, such as by heating and/or cooling the heater spreader structure.