A patient on the veranda of a sleeping chalet with wide<unk>  windows at the Hailey Sanitorium in Wallingford.<unk>  is the therapeutic use of fresh<unk>  and sunshine. In a hospital or sanitorium, this may be done by ensuring good ventilation in an<unk> y, sunny room or by housing patients outdoors in tents or other<unk>  forms of accommodation. During the 20th century, such<unk>  was used for people with infectious respiratory diseases such as influenza or tuberculosis. In the 1960s, researchers into biological warfare found that microbes such as Escherichia coli were killed when exposed to outdoor<unk>  but that, when they were enclosed, they would remain viable for longer. They called this the<unk> <unk>  factor but were unable to identify the exact mechanism or disinfecting agent.<unk> -air schools were established in several countries to provide a healthy environment for sickly children, emphasising fresh<unk> , good food and exercise. In England, the first one<unk> ed at Bostall Wood in 1907 and, by the 1930s, there were over a hundred across the country.
Open-air treatment
Railway surgery
Surgical sieve
Aspiration therapy
Damage control surgery
Laryngotracheal reconstruction
Helmet removal 
First rib resection