Keep it cool.
Jenny Chang / BuzzFeed
Cool down a hot car quickly by opening the passenger window, then opening and closing the driver’s-side door five to six times.
See it in action in this video.
BuzzFeed Blue / youtube.com
If the air outside is too hot to actually cool down your car, roll down or crack your windows, turn on the AC, and start driving.
Once you feel the AC get cold, close the front two windows; a little bit later, close the back two. Watch an explainer of this technique here.
Wherever you can, park in the shade.
Yes, this is obvious, but it makes a big difference — your car is basically an oven, especially if it has a dark paint job. The less direct sun, the better.