300px An<unk>  consists of a canopy placed over the head and shoulders, or over the entire body of a patient to provide oxygen at a higher level than normal. Some devices cover only a part of the face.<unk> s are sometimes confused with altitude<unk> s as used by athletes and those looking to acclimatize to a higher altitude, but those contain a reduced oxygen content. This form of treatment is often prescribed in conditions where people have difficulty in breathing. An<unk>  can be used in either a hospital setting or outside a health-care facility, and can be recommended for short- or long-term therapy. Typically the<unk>  is made of transparent plastic material. It can envelop the patient's bed with the end sections held in place by a mattress to ensure that the<unk>  is airtight. The enclosure often has a side opening with a zipper.
Oxygen tent
Oxygen mask
Gas mask
Venturi mask
N95 respirator
Pocket mask
Oxygen concentrator
Air purifier