What an interesting application...just helps to highlight the limits of relying on the code to cover every situation!
Looking at it from a design only standpoint.. you are describing receptacles that are likely to be used in rather chaotic circumstances, with poor lighting, with folks running about with more on their minds than messing about with covers!
So what would I do? I think that "in use" covers are inappropriate. Where possible, I'd like to see the outlets facing "down", rather than "out." This, of course, mandates an exposed box.
I am afraid that GFI's would be too likely to nuisance-trip- and imagine resetting them with gloves on! Firefighter gear is also quite protective. Yet, I'd like to see some sort of protection...AFCI's, perhaps?
Does your area also require there to be a phone at those locations? In that case, perhaps mounting the receptacle in that enclosure would work.
Just some idle thoughts.