Ah...Florida and humidity and cameras - what a combo! We Floridians have been dealing with this for a long time. A few things we typically do to at least reduce the effects ahead of time:
Store camera and lenses to be used in a room with less AC - like closets or bathrooms. Placing the camera and lens in a sealed plastic bag, and adding some dessicant in the bag, can also help avoid the moisture building inside the lens or camera (you may still get lens fogging from the temperature change, but the bad moisture will be lessened). Often, wrapping the camera in a thick blanket or towel can help it stay more moderate in temperature than when it is more exposed to the air conditioning. Also, if you happen to have anything in the room which generates mild heat, you can store the camera bag on top of this - next to refrigerators, inside a recently used washing machine or dryer (if you're in a DVC villa) - any of these machines which heat up during operation and can keep the bag and its contents a bit warmer.
When you are preparing for a day of shooting, as mentioned above, it is best if you can find a spot outside where you can safely place the camera to warm up, preferably in the direct sun. When traveling in hotels with a private balcony, I'll place my camera bag out there while I have coffee or change in the morning...by the time I'm ready to head out, the camera will usually have equalized. To speed the process, direct sun will quickly heat lens barrels, and take lens caps off so the glass can be exposed to the sun and warm up more quickly. If you have a zoom lens, cycle it in and out a few times, as that can help 'suction' the cool air out of the barrel. Time is really going to be your best ally - plan ahead and give the camera time to equalize. If you have no safe outdoor areas, you can warm up the camera indoors by turning off the air conditioning, and placing the camera and lens on a windowsill exposed to direct sunlight - even better if you can place the camera and lens inside a thin black material like a T-shirt...this will let the dark cloth absorb the heat from the light and warm the camera faster.
While out shooting, bring along a bag that you can place the camera in when transferring from outside to inside...this will be harder if you're dealing with a body-mounted 400mm or bigger lens, but large plastic zip-loc bags can usually accomodate a full-size DSLR and smaller lens. I keep a few large freezer bags in my camera backpack - when I'm in the Caribbean and heading in and out of air-conditioned shops from the humid streets, I'll place the camera inside the freezer bag, then put it in my backpack...this helps avoid building up the moisture each time the temperature and humidity changes. Some dessicant in the bag is always a good idea - you can buy some, or even 'borrow' some (free sources of dessicant abound - often shipped with new shoe boxes, some clothing, various electronics boxes, etc.).
Hope that helps!
