Abstract: An apparatus (1) for use humidified gases delivery treatment comprising a housing, a humidifier, and a chamber heating base connected to said housing, said housing includes a pressurized gases supply, a humidifier engagement (17), a pressurized gases outlet (4), a humidified gases return (7), and a patient outlet (9), said humidifier includes a humidification chamber (2) having a base, a humidifier inlet (5), a humidifier outlet (6) and said chamber is engagable with said humidifier engagement (17) via a single motion, and said single motion of engagement urges the base of said humidification chamber adjacent and in contact with said chamber heating base and makes a first fluid connection between said pressurized gases outlet (4) and said humidifier inlet (5), and makes a second fluid connection between said humidified gases return (7) and said humidifier outlet (6), with said first and second fluid connections being made in the direction of said single motion.