Apparatus and methods for treating a target tissue by delivering a fluid at a defined temperature to a patient's body. An apparatus of the invention includes a fluid delivery unit for delivering fluid in at least close proximity to the target tissue, an aspiration unit for withdrawing the fluid, and a fluid source unit for providing the fluid at the defined temperature. A method of the invention includes forming a void in at least close proximity to the target tissue, and circulating a preheated fluid through the void, wherein the target tissue undergoes adjustment from body temperature to a treatment temperature due to heat exchange between the fluid and the target tissue.