An apparatus for humidifying breathable gas includes (a) at least one humidifier
part configured to retain a body of liquid therein and defining at least one chamber
therein, (b) an inlet communicated with an interior of the at least one humidifier
part and connectable to a blower outlet, and (c) an oulet communicated with the
interior of the at least one humidifier part and connectable to a patient supply
conduit. The at least one chamber is arranged such that liquid from the body of
liquid is prevented from exiting the at least one humidifier part through the inlet
thereof when the at least one humidifier part is rotated from a working, upright orientation.