I know that formally, space is not a vacuum due to quantum fluctuations and what not, but let's neglect those for the moment. Let's say you go from an environment at room temperature and atmospheric pressure to space rather quickly. How would it feel to the bare skin? Background radiation says the space' temperature is only a few Kelvin, but since it's (almost) empty, you could say its temperature is undefined... hence.... how would it feel? If we assume this was the only problem in survival, how long would it take to cool down? Of course, breathing is the biggest problem. If you hold your breath, organs will explode due to the pressure difference, and you'll encounter the same problem with a scuba diving breathing mask, no matter what mixture (?). So, the only option is to immediately exhale. Would pressure problems still destroy you or could you enjoy 10-20 seconds in space before passing out from hypoxia?