Abstract: An applicator (11a-g) for the surface application of a gaseous medium to a part of the body of a living human or animal organism, comprising a gas passage side (21) provided with a plurality of through openings (22) oriented towards the part of the body to be treated during application. A device (13) is also provided for supplying a gas or gas mixture to or onto the gas passage (21), embodied in such a way that at least a part of the gas supplied during operation of the applicator flows through the through openings (22) of the gas passage side (21). A three-dimensional structure (15) is provided on the gas passage side (21) to enable the gas to be finely distributed parallel to the gas passage side (21), whereby the medium flowing out of the gas passage side (21) has an even temperature and volume distribution.