I never refrigerate a fondant-covered cake, which of course means I can't use any fillings that need refrigeration (like fresh fruit and custard). The condensation that forms on it when you take it out is enough to ruin it, and in a hot, humid climate it will never dry. There is one way around this, but it's a bit of work: put your finished cake in a box, then wrap the box in several layers of plastic wrap before you put it in the fridge or freezer. When you take it out, let it come to room temp before you unwrap it. Then the condensation will form on the outside of the box and not on the surface of your cake.
Oh, yes, one other thing: besides making your fondant a little sturdier for hot climates, it helps not to put too humid an undercoating on the cake. I generally use ganache instead of buttercream or apricot jam, which are the more common things to use, and make it a very thin layer. Hope some of this will help your cakes. I know when I moved to CancĂșn from a very cool, dry climate, it took me a while to find a good solution to these problems. Best of luck!
Marianna
"I know my own mind...and it's around here somewhere!"
Marianna
"I know my own mind...and it's around here somewhere!"