HEFEL KlimaControl Comfort mattress toppers guarantee an ideal sleeping environment. They always feel pleasantly dry even when exposed to strong perspiration. This is achieved by the natural fibre TENCEL™ Lyocell in the filling. The exceptional microstructure of TENCEL™ Lyocell disperses more moisture and vapour from the body than any other fibre. Furthermore this process does not create a film of water on the skin in which bacteria can establish themselves.