We have all seen countless science fiction movies where someone is in space when their helmet gets a crack, their room loses its normalized pressure, or they are thrown out of a spaceship. The following scene varies from a man slowly freezing to death (usually if he has a nice monologue to deliver) to his head exploding like a balloon if they are looking for something a little more dramatic. There are very few, if any, movies that accurately portray what would happen if you were exposed to breathing in outer space.
There have been a number of studies in this area on dogs, chimpanzees and even humans. The dogs appear to have been the first studies to take place and as a dog lover I have to say the results are rather upsetting. I will put everything that happened to the poor dogs in this paragraph only. If you don’t want to know, skip to the next paragraph now. Dogs were exposed to an atmospheric pressure similar to space, 1/380th of what we are used to on Earth. In nearly every test the dogs survived if the test was less than 90 seconds long, any longer and the dogs had a heart attack and died. In the 90 second cases though they still went through a lot. The dogs were reported to become unconscious after 10 to 20 seconds, they would urinate, vomit and defecate in the same moment, they would have seizures, and in some cases their bodies swelled to twice the original size.
The good news is that any dogs who tested under 90 seconds all survived without any long term issues. Chimpanzees were next to be studied and could last longer than dogs, they were able to go for 3 minutes without serious issues.
Humans have been tested as well, although not on purpose. There have been numerous accidents over the years that have shown us how humans would respond to such conditions. It is nothing like the movies. In one case an accident resulted in an astronaut being exposed for 27 seconds and although falling unconscious he had no serious side effects in the long term. In another case a chamber lost its pressure for about three minutes. This was too long and the man was only able to gasp for breath before dying.
This shows that man would be able to survive in space somewhere between 90 seconds and three minutes without serious side effects. While it would still not be recommended it appears it could be overcome. This is a far cry from the movie depiction of skin freezing or boiling on impact. Although those who have experienced it say the tongue gets very dry from the lack of moisture in the air. Why has no movie ever shown that?