A system and method for providing greater control over the temperature of a thermal treatment element of a medical device, enabling an operator to extend a thawing period of a cryoablation procedure. The system may include a fluid flow path that bypasses a subcooler, giving the operator selective control over the temperature of refrigerant delivered to the treatment element and, therefore, treatment element temperature. Additionally or alternatively, the system may include a fluid delivery conduit that is in communication with a liquid refrigerant and a gaseous refrigerant. Adjustment of the ratio of liquid to gaseous refrigerant also offers control over the treatment element temperature. Additionally or alternatively, the system may include one or more valves and/or heating elements in the fluid delivery and recovery conduits to control the treatment element temperature.