An endoscopic instrument includes a first instrument part adapted for introduction into a cavity of a human body and having an introduction channel therein for passage of gas therethrough, and a second instrument part having a connection channel therein adapted to be connected to the first instrument part introduction channel. The second instrument part is adapted for connection to a gas source to provide gas, at a flow rate suitable for insufflation of a human body cavity, from the gas source through the connection channel to the introduction channel for introduction into the human body. A heating device heats the gas in the introduction channel to substantially the temperature of the human body.