A water chamber (1) adapted for use in conjunction with a heater base, for humidifying an air stream. The chamber (1) including at least one horizontally oriented gases port (3) including an elongate flow tube (5) extending into the chamber (1) from the inner periphery of the gases port (3), the flow tube (5) having an opening at its distal end facing a direction transverse to the axis of the tube (5).
