Basic Action Super Heroes!

Vacuum, radiation, insane temperatures. Space is a dangerous place, especially for supers who don't have any of the immunities to such an environment.

So... game mechanic wise, what happens with exposure to space? I didn't find anything in the rule book. I guess I could just chalk it up to drowning and use those rules.

That'd work. BASH! Sci-Fi has a lot more detail about it, but for a supers game, using the drowning rules should be enough. Maybe make it a little worse, like add to the severity of the rolls or something.