Systems, methods, and devices are disclosed for humidifying a breathing gas that reduces and/or eliminates the dangers and discomforts experienced by a patient. In one aspect, a system for humidifying gases includes a body, extending along a first axis from a first face to a second face, a first lumen at the first face, through which fluid enters the body, a second lumen at the first face through which fluid exits the body and a nonporous membrane located inside the body and extending from the first face to the second face wherein gas moving through the nonporous membrane is humidified by the fluid.
