It's 90 degrees with a "feels like" temp of 103 and you think with cracked car windows and a battery operated fan the dog should have been fine left in a car while you shop?
That feels like heat index of 103 is calculated if you are standing in the open air outside, not locked in a metal hot box without a trace of shade! Don't be stupid, take your dog for it's favorite things when the weather permits and not when it puts it's life in danger!