The players are pretty big - about four times the size
of a DVD player
(at least), not to mention quite heavy (for what they are). I doubt
they'd be allowed on as carry-on luggage.
It's the vibration I'd be bothered about rather than any temperature
issue though. The quality of the solder work on all the players I've
been inside is about the worst I've seen on any electronic equipment,
I never even considered temperatures, I'm simply thinking of how non-carryon
luggage is treated. You don't want some idiot deciding to see how far into
the pile the box can be thrown.
As for the size, it doesn't look that much larger than a standard Laserdisc
player (though it looks a little thicker than most).
Zane