The present invention relates to a heater of a medical device with a receiving element for at least one part of a liquid-carrying component, wherein the receiving element at least partially and/or substantially encloses the one part of a liquid-carrying component and comprises an opening toward one side, the part of a liquid-carrying component being introduced through the opening into the receiving element. The invention further relates to a medical device comprising a heater, a method for upgrading a medical device, a tubing set having at least one heating bag and to a system comprising at least one heater.
