Experience at Aalborg University Hospital's Department of Pulmonary Medicine (Lungemedicinsk Afdeling) in Denmark gives rise to a renewed interest in the investigation of the properties and effects of humidification in COPD patients in LTOT. For the last 5 years, the department has discharged fibrosis patients with oxygen flow > 6 l/min with a warm mist humidifier. The initiative has given clear indication that infection ratios can be reduced and the QOL increased. Many COPD patients experience improved oxygen saturation when oxygen treatment for respiration insufficiency is given with warm humidification.