A nerd that I used to work with had a car AC that wasn't cool enough, and asked me for advice. Told him how to add refrigerant to the system, and told him to keep running the AC while he was doing it. Told him to go slow and
not to add another can, after car was cooled off..
But, he (being a nerd) looked up the specs for the AC and measured the vent output temperature. It was out of spec. He wanted it perfect, and added can after can..
It was super hot (August) and he took the wife and new baby for a long ride down to the cape.
After they got stuck in heavy traffic, you can guess what happened..