In 90 degree plus heat it can reach over 110 degrees in a matter of minutes inside a car. An animal can die within 15 minutes.
Law enforcement, firefighters and humane officers In Pennsylvania can break a window to rescue an animal. In New Jersey, however, it's a different story.
"Like a baby they don't last long once the temp goes over a 110 or so, they die quickly," said Vet. Robert Blease of Common Sense for Animals.
The 53-year-old New Jersey vet says he knows what he would do if he saw an animal locked in a hot car.
"I can assure you if I came across an animal without an owner parked in the sun in a car I would smash the window," he said.
It is illegal to have a pet in a hot car, and fines can be between $250 and $1000. It's also illegal for New Jersey law enforcement to break a window to save them.
Pennsylvania recently enacted its hot car law allowing police, firefighters and humane officers to break a window for an animal in distress without facing liabilities.
Kids are also at the forefront of the issue. Pennsylvania recently upped its kids in cars law.
"This provides a cover for those that do utilize appropriate force from a vehicle not held for civil liability," said Trooper Nathan Branosky of the Pennsylvania State Police.
According to website Kids and Cars, 21 kids have died in hot cars across the United States this year.
Since 1995, 12 kids have died from being in hot cars in Pennsylvania.
The new bill passed July 15 allows for good Samaritans to rescue kids from hot cars and remain free from legal issues.
"Have to make every means possible for contacting driver of vehicle, law enforcement and emergency responder." Branoksy said.
You also have to stay by the car until help arrives.
As for New Jersey's law regarding animals, if your pet dies as a result of being in a hot car, you can face felony charges.