The quarter glass!
They’re usually more expensive to replace and easier to smash.
Unless you’re actually trying to save someone, and speed is necessary…
Then it’s the side windows opposite where the person is (I.e. of the dog is in the front passenger, the driver side rear.)
This helps avoid causing injuries from the glass shattering
Also, call emergency services first, unless the kid is clearly about to die. (If they’re more or less alert you still have time to pass that liability off.)
I’ve worked security for a parking lot.
We’ve had several instances of people being drunk/oding, several people leaving kids and pets on cars for what would be expected to be 4+ hours.
It was a cop who told me about the quarter panels being more expensive. To be fair that particular incident, a toddler was less than alert but not unconscious. They got arrested for child endangerment/abuse (the cop sat on their car until the event let out and they came back. She was pissed.)
For pets, they’re technically property, so it’s best to let animal control make that decision- there’s some strict rules that might see you in jail. Emergency services can connect you to animal control, so if it’s bad enough they can tell you to do it and remove liability from you.