I just got back from Borneo. Hot, humid like devils armpit, heavy tropical rains.
I brought D700, couple of lenses and a plastic raincover. I used them in all conditions including dragging the camera exposed to all kinds of elements through a 5 day jungle hike, only using the cover once storms were coming on. As expected, the camera handled it like it should, and it was undoubtedly just a fraction what it can handle.
In the hindsight I could have brought most any camera, but I didn't know what to expect (coulda spent weeks in open monsoon) so I decided to rely on D700.