An oxygen mask is a device used to deliver oxygen to individuals who may have difficulty breathing. It is commonly found in airplanes, hospitals, and emergency medical situations. The mask fits over the nose and mouth, allowing the user to inhale oxygen from a connected supply, ensuring they receive adequate air. In airplanes, oxygen masks are deployed automatically when cabin pressure drops, helping passengers breathe until the aircraft descends to a safer altitude. In medical settings, they are used for patients with respiratory issues, such as those suffering from asthma or COPD, to improve oxygen levels in the blood.