Does it really need to be stated (again) that you shouldn't leave your pets alone in a hot car? It's the "hot" part of the equation that matters, not how many pets you leave. We've known for decades that it's a bad idea to leave pets in hot vehicles. Just check out this retro PSA from the Humane Society: Some groups use humor to try to get the point across, but the message is the same: don't do it! If you still think it's okay to leave them alone "just for a few minutes", take a look at how long a human can stand being in a car. The internal temperature of the car quickly goes from 75F (24C) to 104F (40C). So even if the temperature outside seems mild, don't think that means it's safe to leave you car alone.  The interior of your car can heat up quickly -- just think about how hot it is when you come back to the car after 10 or 15 minutes away.  A dog or cat can sustain serious internal damage in a matter of minutes if the internal temperature of the car gets above 100F and every year there are reports of animals dying when left in a car unattended. Just don't.