In an effort to determine the effects of alcohol upon the time of useful consciousness of a subject when he is suddenly subjected to hypoxic conditions, ten normal subjects were taken to an atmosphere simulating 25,000 feet (288 mm Hg) in an altitude chamber. After their oxygen masks were removed, they performed various tasks requiring mental and physical coordination until definite hypoxic symptoms were manifested. Later, these same subjects were submitted to identical conditions after the administration of 0.5 cc of 100-proof whiskey per pound of body weight. Blood alcohol levels were determined upon the completion of experiment. A comparison of results demonstrated a 38% reduction in the time of useful consciousness under such hypoxic conditions. In the age of pressurized aircraft subject to rapid decompression, this 38% reduction may easily spell the difference between life and death.