A thermal regulation catheter system and method of use are disclosed, for moderating the temperature and other parameters of tissue surrounding a target tissue for an ablation procedure, or for performing a thermal treatment procedure. In an embodiment, the device includes a catheter having a shaft with a fluid supply line and a fluid return line disposed therein, and an inflatable heat exchange vessel at a distal end of the shaft. The fluid supply line supplies fluid to inflate the heat exchange vessel, and the fluid return line conducts fluid away from the heat exchange vessel.