To all those who did not read the article linked by Ryu_Liew.

If you don't try to hold your breath, exposure to space for half a minute or so is unlikely to produce permanent injury. Holding your breath is likely to damage your lungs ... You do not explode. Your blood does not boil. You do not freeze. You do not instantly lose consciousness ... You do not instantly freeze because, although the space environment is typically very cold, heat does not transfer away from a body quickly ...

It also refers to an accident in a vacuum chamber at NASA's Manned Spacecraft Center where Jim LeBlanc was exposed to near vacuum for about 15 seconds. There's a video of the incident at http://vodpod.com/watch/3935109-nasas-jim-...m-accidentvideo