At 50 degrees, as long as not gut shot, a couple hours isn't gonna hurt.
I agree, although if I know I have to wait an hour or so (As in, trapped four hogs and it's gonna be a little while before I get to the last one) I'll hose 'em down to try to help cool the meat. Then I make sure they're lying in the shade. At night, of course, I don't worry about the shade thing. But then, I generally check traps in the morning. I hate staying up 'til midnight cleaning hogs.