On an related personal anecdote -- if you ever want to feel what's it's like to open your mouth in a vacuum and get a taste of what it would be like to do so in

On an related personal anecdote -- if you ever want to feel what's it's like to open your mouth in a vacuum and get a taste of what it would be like to do so in space (save the lack of any heat) you can always do what I did by accident as a kid: Swim in a pool that has a flexible plastic (in this case, a thin-bubble wrap sort of material) sheet floating over half of the pool, swim under part of the covered area, and then stand up out of the water. The sheet will lift up, but there will be no air whatsoever. Open your mouth, and find all of the air in your lungs immediately sucked out with no way to take a breath -- pretty horrifying if you're not expecting it...