I'm making a cake for an outdoor even at the local high school. It's going to be 35 degrees out (95F) which is so hot for up here. The plan is chocolate cake with cookies and cream filling, and vanilla cake with lemon cream filling covered in buttercream. Will this hold up in the heat? will it spoil? I really don't want anyone becoming sick....any suggestions would help. I've never had a cake due in this kind of heat.

Your cakes aren't likely to spoil but the frosting will melt in the heat, especially if you're using butter or margarine. Try Indydebi's buttercream recipe. It's not totally heatproof but the only time I've had trouble with it was when the temp was over 100.

Honestly, I wouldn't want to leave a cake in the heat for more than 1 hour.