A system for humidifying ventilation gas, the system comprising:- a ventilator (601)- a patient circuit (605) in fluid communication with the ventilator at a proximal end and fluidly connected to a patient airway at a distal end, wherein the patient circuit has an inner diameter of approximately 2 - 14 mm- a fluid reservoir (609)- a humidification device and- a channel between the humidification device and a distal end of the patient circuit.
