A pressure suit is a protective suit worn by high-altitude pilots who may fly at altitudes where the air pressure is too low for an unprotected person to survive, even breathing pure oxygen at positive pressure. Such suits may be either full-pressure (i.e. a space suit) or partial-pressure (as used by air crew). Partial-pressure suits work by providing mechanical counter-pressure to assist breathing at altitude.

Diving suits that protect the wearer from excessively high pressure are called atmospheric diving suits. Pressure suits in general are examples of environmental suits.

The region from sea level to around 10,000 ft (3,000 m) is known as the physiological-efficient zone. Oxygen levels are usually high enough for humans to function without supplemental oxygen and decompression sickness is rare.

The physiological-deficient zone extends from 12,000 ft (3,700 m) to about 50,000 ft (15,000 m). There is an increased risk of problems such as hypoxia, trapped-gas dysbarism (where gas trapped in the body expands), and evolved-gas dysbarism (where dissolved gases such as nitrogen may form in the tissues, i.e. decompression sickness). Above approximately 34,000 ft (10,000 m) oxygen-rich breathing mixture is required to approximate the oxygen available in the lower atmosphere, while above 40,000 ft (12,000 m) oxygen must be under positive pressure. Above 63,000 ft (19,000 m), also known as the Armstrong limit, fluids in the throat and lungs will boil away. Generally, 100% oxygen is used to maintain an equivalent altitude of 10,000 ft (3,000 m).

Felix Baumgartner (born 20 April 1969 in Salzburg, Austria) is an Austrian skydiver and a BASE jumper. He is renowned for the particularly dangerous nature of the stunts he has performed during his career. Baumgartner spent time in the Austrian military where he practiced parachute jumping, including training to land on small target zones.

He was born on 20 April 1969 in Salzburg, Austria.

In 1999 he claimed the world record for the highest parachute jump from a building when he jumped from the Petronas Towers in Kuala Lumpur, Malaysia.

On 31 July 2003, Baumgartner became the first person to skydive across the English Channel using a specially made fibre wing.

Baumgartner set the world record for the lowest BASE jump ever, from the hand of the Christ the Redeemer statue in Rio de Janeiro.

He became the first person to BASE jump from the completed Millau Viaduct in France on 27 June 2004^{[citation needed]} and the first person to sky dive onto, then BASE jump from, the Turning Torso building in Malmö, Sweden on 18 August 2006.