Marios Forsos , Jul 06, 2010; 03:01 a.m.
The rain, while problematic, is something your rain cover can easily handle (along with some care on your behalf). What will be a bit more of an issue is humidity. And more to the point, the differences in humidity between your hotel room and the outside. For that purpose, your ziploc bags will come in very, very handy.
Whenever you walk in or out of the room (actually, just before), place your camera WITH a lens attatched into a ziploc bag, push out all the air and close it tightly, forcing all the air out. Then carry the camera inside (or outside). Once there, leave it to aclimatise for approximately 10 mins (depending on the differences in temperature and humidity) and THEN take the camera out.
In terms of cleaning the lenses AFTER a day's shooting, make sure that whenever you open your camera you do so AWAY from any airconditioning unit as it WILL blow particles into the camera. Place a clean cotton cloth on a steady surface, away from windows, etc, and carefully clean your camera with a dry cloth. Avoid alchohol-based solutions as the humidity will alter the chemical composition of the liquid and create more problems than it will solve.
In terms of sensor-cleaning, take a blower with you AND a wet cleaning solution. Humidity WILL cause some particles to stick to your sensor and you will need a liquid solution to remove them.
I hope this helps. Take care and have fun