The RapidBlue Endovascular Cooling & Warming System is a closed-loop, catheter-based system that can modulate whole body temperature without fluid induction. It consists of a disposable endovascular heat transfer catheter, administration cassette and a console. The distal portion of the catheter has a flexible, metallic temperature control element (TCE) that is cooled or warmed by sterile saline circulated within it from the RapidBlue Console. The administration cassette connects the catheter to the console, maintaining the sterility of the saline conduit. The TCE does not expand inside the body so the outer diameter of the TCE will remain consistent throughout the entire cooling/warming procedure.