I didn’t wan’t to get into the other thread on this subject, but you’ve dragged me into it. They’re not supposed to be doing that. End of story. They are supposed to be seated and belted. What FDNY does is their own issue to deal with, but that’s the view of the rest of the fire service. We retired a heavy rescue in my department in 2007 that had a bench seat in the box with the single door off the back. If you were caught standing while the truck was moving there was (at the least) a stern talking to; in a few cases there was some time off to think about their decision to stand up. Like I said on the other thread, though, it’s hot and stinky back there, leaving the door open isn’t a bad idea to remedy that situation.