I saw your post from last night about AZ and just wanted to help out bc I live in Phx!! I would definitely turn the car/ac on for a bit before you put lo out there..it helps to cool the seat down. Also..bring it inside if you can...we try to do that a lot. Bring lots of sunscreen, water, hats, etc. Our ds usually wears a onesie and shorts, but he is used to this heat so just a onesie might be great. He does sleep in a sleeper though because we keep the house really cool at night so definitely bring some warmer stuff because we love our ac here! I hope you have fun, and maybe get to swim too while you are here!! Plus we have been having a lot of monsoon storms so it had at least been a bit overcast.