I am not sure how much the heat factors into it. This is an interesting link explaining why concrete may crack. We always assume that yes...concrete WILL crack. The trick is to create the correct scoring/control joints so that the cracks occur within those joints. It is EXTREMELY important to hire an excellent concrete contractor. Good luck!

Yes, as stated by Prideaux Design, hiring a quality concrete finisher is absolutely essential. There is far more to concrete than most people have any idea about (mix designs, water reducers, time of year, sun or shade during curing, substrate preparations, style and type of finish, color oxides - just to name a few points of focus) that a local expert will understand. These folks can be hard to find, but it is essential to the outcome.