I am always skeptical about these naked spacewalks for various reasons They say our body is 70 water but that does not really paint an accurate picture The reality is that we are more like soda pop in a bottle where we have a certain amount of nitrogen oxygen and other trace gasses dissolved in our bloodstream at STP The key here is the STP part As with a bottle of soda when the pressure is decreased the gasses rapidly come out of solution which is what produces the fizz Similarly if your body went rapidly from STP to the vacuum of outer space you would almost certainly experience a similar effect To be blunt your blood would quite literally boil and you would surly die of an aneurysm or internal bleeding from all the vessels which would be breached by the gasses trying to escape About the closest I ve seen to this being accurately portrayed is in the film Event Horizon where it shows all the vessels on Justin s body becoming visible as they rapidly expand when the airlock pressure is decreased But still it does not explain where the gas goes which is the same problem in this film It seems wholly impossible to survive such a drastic change in atmospheric pressure