Hi Alyssa - for some reason, my computer blocks me from posting to discussions, but wanted to let you know that kneading your fondant in cornstarch mixed with powdered sugar really helps make it stand up a little better in the heat. I use mm fondant all the time, and I put my mm covered cakes in the fridge no prob :)

Hey Alyssa, it depends on how sticky the fondant is - if its really sticky, i do half/half, otherwise, i just throw a dash of cornstarch into the powdered sugar on the counter before i start kneading. I hope you find the tip helpful!!