A medical device for thermally affecting tissue, the medical device comprising: an elongate body including a distal portion and a proximal portion ; an actuation element slidably disposed within the elongate body , the actuation element including a distal portion and a proximal portion; an inflatable treatment element having a body portion that defines an interior chamber, a first neck , and a second neck , the first neck being coupled to the distal portion of the elongate body , the second neck including a first portion adjacent to a second portion and being coupled to the distal portion of the actuation element , the second portion being immediately proximal to the first portion and being not attached to the actuation element , the first portion and the second portion each having a diameter that is less than the body portion; and a fluid injection element located within the interior chamber of the treatment element , the fluid injection element having a first configuration in which the fluid injection element is substantially in contact with the actuation element and a second configuration in which at least a portion of the fluid injection element is expanded away from the actuation element , retraction of the actuation element within the elongate body causing the treatment element to transition from a first configuration to a second configuration, the second portion being folded over the first portion when the treatment element is in the second configuration, the fluid injection element being in the first configuration when the treatment element is in the first configuration and the fluid injection element being in the second configuration when the treatment element is in the second configuration. an elongate body including a distal portion and a proximal portion ; an actuation element slidably disposed within the elongate body , the actuation element including a distal portion and a proximal portion; an inflatable treatment element having a body portion that defines an interior chamber, a first neck , and a second neck , the first neck being coupled to the distal portion of the elongate body , the second neck including a first portion adjacent to a second portion and being coupled to the distal portion of the actuation element , the second portion being immediately proximal to the first portion and being not attached to the actuation element , the first portion and the second portion each having a diameter that is less than the body portion; and a fluid injection element located within the interior chamber of the treatment element , the fluid injection element having a first configuration in which the fluid injection element is substantially in contact with the actuation element and a second configuration in which at least a portion of the fluid injection element is expanded away from the actuation element , retraction of the actuation element within the elongate body causing the treatment element to transition from a first configuration to a second configuration, the second portion being folded over the first portion when the treatment element is in the second configuration, the fluid injection element being in the first configuration when the treatment element is in the first configuration and the fluid injection element being in the second configuration when the treatment element is in the second configuration. <EOS>