Question: If you go into space without a space suit, then what will happen?

Hayley Evers-King answered on 12 Mar 2013:

The first thing that would kill you is the lack of oxygen. You’d suffocate and be completely brain dead within three minutes. If you held your breath, the pressure difference would cause the air to expand, rupturing your lungs and releasing air bubbles in to your blood stream (a similar thing happens to scuba divers who surface too quickly). All in all, it’s probably not a good idea!