What most people don’t realize that on a mildly warm day in the 80s, the inside of a car can go up to 100 °F or more in just 10 minutes. On a hot summer day, it just takes a few minutes for the inside of the car to heat up to over 120 °F. Even if you leave all of the windows cracked open, a hot car can be perilous to the safety of your pet and can lead to a fatal heat stroke. In some states, leaving pets unattended in cars in extreme weather is illegal and can subject you to fines of up to $2000 . Even if you only plan to be out of the car for just a few minutes, please don’t leave your pets in the car anytime the outside temperature is over 60 °F, even in winter, even with the windows cracked, and even in the shade. (source) Car interiors get too hot for a pet in a very short time. A short delay in your getting back to the car quickly can be fatal to your pets.
