Is it safe to leave perishables in a cooler inside a hot car?

No, it is not safe. A sealed car becomes a solar oven, and even a good cooler can’t keep food below 40°F when the interior hits 140°F+ for hours. The ice melts faster than you think, and food enters the danger zone within two hours. If you must stash a cooler, park in deep shade, open windows slightly, use a ton of ice, and keep it out of direct sun—but honestly, pack non-perishables like peanut butter, trail mix, and dried fruit instead.