and what i sugest doing is getting the fan upgrade (the one that mounts on the side of the xbox) this will keep it from over heating
now about the humidity, their is this special stuff that u can put on electronics that will make them water proof (my friend has it and he was able to run his rc car under water, engine off cause he didnt have any tubing for the intake and exaust)
that should pretty much solve ur worries
good luck
