A girl just got arrested for doing this in Phoenix. Luckily a guy walked by a minute or so after she left and apparently he called 911 rather than break open the window. The baby survived and is fine however.
Mind you, it's 105 plus in Phoenix this time of year.
It took them 30 minutes to find her in Walmart.
In our desert (Coachella Valley), you'll get arrested even if you tie your dog to the outside of your car - to avoid getting arrested for leaving it inside - if the pavement is hot.
Hence, we're rather used to seeing people walking their dogs through the grocery section of the local Wally.