An assembly of devices used with a laparoscopic gas distention system or other gas source to condition the insufflation gas stream [typically carbon dioxide (CO2)] by heating and humidifying the gas before introduction into the peritoneal cavity or a wound during laparoscopic or open surgery. It typically consists of a mains electricity (AC-powered) control unit, a humidification chamber through which cold/dry gas passes for conditioning, and a tubing set for connection to the gas source and delivery of the conditioned gas to the operative site. Conditioning of the gas helps alleviate problems associated with gas insufflation, i.e., desiccation of internal tissue and body temperature loss.