The AY safety video (at least on LHR-HEL-LHR) has words along the lines of "we discourage you from spending time in the aisles or door areas". I've often wondered how long it will be until someone gets a DVT* and the video undergoes a hasty update.

*yes, I know there are many reasons for clots, and one should assess own risks and move about as needed. But the mindset of many is that they are a problem connected to flying.