the humidity has gone through the roof here in past three days and now my best friends cake is melting!! i have never had this happen before it is a pillow cake and the tassles are melting of and the fondant has gone all sticky and soft how do i fix it????? party is this arfternoon please help!!!!!!

I'm not sure there is anything you can do except move the cake to a cool room. In the future you may have to had some tylose to help firm the fondant due to humidity issues. How much tylose? You'll have to experiment. Just try a measured amount each time you try it until you get it right, then write it down in a cake journal so you always know what techniques worked for you.