A canister-like device that, when used together with a dedicated humidifying insertable filter, connects in-line with a patient's artificial airway [e.g., an endotracheal (ET) tube] to capture the patient's exhaled heat and moisture so that they can be used to heat and humidify therapeutic gases inspired by the patient; it does not include a microbial filter. Commonly known as a heat & moisture exchanger (HME) or an "artificial nose", it is used when the patient is subjected to extended periods of breathing dry gases such as during anaesthesia or intensive care ventilation. This is a reusable device.