A respiration moistener (1) has an inlet (3), into which incoming gas (2) to be moistened can be fed. Vapor (21) is mixed with the incoming gas (2) in a mixing chamber (4). Moistened outgoing gas (5) flows out of an outlet (6). In cases in which the temperature of the incoming gas (2) becomes so high that the temperature of the outgoing gas (5) is above a desired value, the internal desired value is adjusted. The outgoing gas (5) can then cool to the desired value on its way through the inspiration tube (7).
