First, before you even get your cake we are making changes to protect the cake from the heat and humidity. During warmer months we make sure to make the icing a little bit thicker. This will give the cake a harder coat, which would take a little longer to get droopy in warmer climates. Second, we make sure the car is as cold as possible during transport. This helps keep the cake from getting soft.
But what about after set up?
For one, keep the cake inside. I know that is somewhat of a given, but outside cakes (especially this time of year) are just not going to work. At all. The cake will melt.
Choose a location for the cake table clear of windows. Windows will produce heat and if the cake is in direct sunlight of that heat it could cause the cake to become droopy.
Kick up the AC. Most venues will want to have the AC cranked up anyway to prepare for a large crowd, but just in case, make sure it's nice and cool inside the venue. This will make sure your cake stays crisp and firm and beautiful for photos.