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's). 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. Black-out and G-LOC has caused a number of fatal aircraft accidents.