Vacuum exposure is deadly, but the human body can stand exposure for a little over a minute without irreparable harm if the proper precautions are taken.
If you have the misfortune of being exposed to a vacuum, for instance, if you are a character in a science fiction story, your body will not explode, but your blood and other fluids may boil, given a long enough exposure. Frost will form in your mouth as your saliva rapidly evaporates. Your ears will pop. Eventually you will die of asphyxiation, if you haven't already had a heart attack from panic.
You have about a minute and a half to get to safety. Before exposure, or immediately after initial exposure, you should exhale and remove all the air from your lungs. Otherwise, the air pressure will rupture the delicate alveoli, the air sacs, in your lungs. That is not an injury that's easy to recover from. There is not much else you can do.
The only accurate depiction of vacuum exposure in fiction can be found in the movie 2001: A Space Odyssey. In the movie the main character is exposed very briefly, and handles the situation well.
