Yeah, in CA you aren't allowed to leave a kid under 6 in a car if "there are conditions that can pose a risk to the child’s health and safety, even if accompanied by another child who is not yet 13. What does it mean for conditions to "pose a risk"? Obviously high heat, but it's not clear what else could qualify.

I don't ever leave my kids (one that is under 6 and one that is well over 6, but not yet 13) alone in a car, since I don't want police or nosy passersby injecting themselves in a perfectly benign situation.