A breathing tube for conducting a gas mixture in a ventilation system is provided, the tube including a tube portion a coupler connectable to the tube portion a connecting piece connectable to the coupler and which is attachable to a tube or a machine wherein a filter element for filtering the gas mixture is arranged between the coupler and the connecting piece.The coupler includes a first integral electrical heating device which surrounds the filter element and which is adapted to heat the filter element effectively.
