I made a 3 tiered cake for an engagement yesterday. I live in Singapore and the weather is crazily hot and very humid! i did everything in the air conditioned room and it was all ok. When it was time to deliver the cake, in the car it started to become sticky. The venue we went to did not have air condition so we had to leave it out and they only cut the cake an hour later... by then the whole fondant on the top tier slid off the cake. I did not know what to do. Please help!! i have a 2 tier cake to do next week and i am terrified!! 

What are you using underneath your fondant? What brand fondant did you use? How thick had you rolled the fondant? What did you use to adhere the fondant to whatever was underneath?

I used ganache underneath. fondant brand was mix of satin ice and bakels.  Around 1/4 inch thickness. i used the fondant smoother. I hope you can help me:(

AI don't know what can be done since it is so hot in your area. You need air conditioning so it won't melt. Buttercream may also not melt as easily as ganache since ganache is just chocolate & cream. So maybe use a stiffened crusting buttercream under your fondant.

I used indydebbi's (sp?) crusting buttercream for a cake that was placed outside during the summer here in NY...very hot, very humid..but it stayed intact.  I also use fondarific fondant I kept the whole thing refrigerated until pick up. No problems the buttercream held up great!

AI have used just a bit of gum paste on hot weather conditions and it works. Lots of luck :)