Abstract: A heat and moisturizing exchanger device for use by patients having permanent tracheostomies when inspiring gases directly from the atmosphere. The device has a collar adapted to be sealingly secured to the neck of a patient with a tracheal opening and having an aperture adapted to receive a replacable heat and moisture exchanger cartridge. The cartridge contains a roll of hygroscopically treated material which collects heat and moisture from expired gas to warm and humidify the gas subsequently inspired by the patient. A nipple is provided for connetion to an auxiliary source of oxygen.