The Pennsylvania State House recently passed a bill that would make it against the law to leave a cat or a dog unattended in a car. The bill makes it illegal to leave a pet in an unintended vehicle where the temperatures reach 80 degrees or more. It doesn't matter whether the windows are open or not.
According to an article in Penn Live, the bill would allow a police officer or other type of first responder to rescue the animal without fear of being responsible for damages. Of course the rescuer must make a reasonable effort to locate the pet's owner.