In ZF you have a table for effects on the body over time. In your game do you have 1:1 Astral Time?
I read somewhere (maybe Dragon 67?) that moments of sleep could be weeks or months on the Astral. MoP has slightly different time keeping? How do you rule on time? (totally possible I missed a sentence in there)
Related question: from a game design question, it seems like if months on the astral are moments on the prime, then the mechanics for body hunger and thirst just don't have teeth.
On the other hand, if its 1:1 time then we miss out on "Randolph Carter awoke and he had lived a lifetime as a king in kadath" or something like that. But you definitely get time pressure.
With 1:1 Astral:Body time, the really tough case is "Traveling to an unknown place takes 50x1d0 aka 50-500hours)
That would mean on a really high roll you'd have to quit before you got there or your body would die and you'd have to try again hoping for a re-roll.
Something like a 1:10 ratio or 1:100 would make most cases trivial for body effects, but would make interesting situations for the Cleric going to Arcadia to live awhile among the dead, or Randolph going to live awhile in Ulthar.