High-altitude parachute jump
In 1943, Dr. William Randolph Lovelace II jumped out of a B-17 bomber flying at 40,200 feet in order to test the emergency oxygen unit he had designed with colleagues. It was his first ever parachute jump. An unaided parachutist at such high altitude would quickly lose consciousness due to lack of oxygen, and unable to pull the parachute ripcord when needed. When he opened his parachute, it was the sudden deceleration of 32 g's, which knocked him unconscious. He lost a glove, and in the sub-zero (-40º F) temperature his hand became frostbitten. The oxygen unit kept him alive. He regained consciousness at a lower altitude, and landed almost 24 minutes after he bailed out. His test led to development of automatic parachute opening devices.«*