An F5 will certainly fare better than most cameras in this situation, but I've never subjected my F5 to such conditions.
My instinct would be to carry a mechanical body like an F2A/F2AS, personally - that way you don't have to worry about electronics. You do lose some convenience, though.
I do have an F2, and I also thought about my early Canon F1 but I value those more due to their age. I also want the speed of the F5 as many of my photos will be of fast moving bikes. I guess I shouldn't be to concerned really as F5s are pretty easy to find but it could get expensive if I have to keep replacing the things.
Various Canons and Nikons. A Mamiya and a Bronica. A couple Brownies, and a Couple of Argus' (Argi?)