Dr. Ryan Stone (Sandra Bullock) has a hard enough time surviving with a spacesuit in "Gravity." Without a spacesuit, it would take mere seconds to asphyxiate.

Because there's no pressure in space, air expands. This means the air inside your lungs would expand and tear through the tissue. And in such an extreme environment, your body would use up all of the oxygen in your blood in about 15 seconds.

Other gruesome consequences of unprotected space exposure would include loss of bowel control, boiling blood, exploding capillaries, and bloating.