G-suit

A g-suit, or the more accurately named anti-g suit, is a flight suit worn by aviators and astronauts who are subject to high levels of acceleration force (g). It is designed to prevent a black-out and g-LOC (g-induced loss of consciousness) caused by the blood pooling in the lower part of the body when under acceleration, thus depriving the brain of blood.

While attempting to shut down the Stargate with a shape-charge, Colonels Jack O'Neill and Frank Cromwell both wore G-suits.