Well, what kind of temperatures are we talking about? I don't think overall it should be a big concern. I don't think ADJ or Elation would release an unsafe fixture, so I suppose it's a non-issue.
Last summer, my amps thermalled because some genius at the hotel disabled the AC for the rave. Talk about sweaty anime funk.... that room reeked with the lack of air flow.
When I was at Disneyland last, now that I've been sufficiently entertained by the many dark rides(which I still enjoy), I look around. I see lots of compact florescent-type fixtures that remind me of those ones you added links to, all over the dark rides. it's interesting how the mentality is in the parks about certain things. With their heavy theming and decorations, you'd think they'd make an effort to at least put some sort of covering to block the fact there's a fixture there. They obviously feel nobody is going to do anything but look ahead. I just can't completely recommend that, because if you do that, you miss a fair amount of other details that are INTENDED to be seen. That's different than what I'm doing of purposely looking for how things work.