A cooler in a hot trunk is fine for a few hours – if you pack it right

Probably, but only if you pack it right.

A trunk in summer can hit 140°F. That’s well above the danger zone for perishable food. A decent cooler holds temps for a while, but it’s not magic. The key is ice volume and insulation.

If you’re using a hard-sided rotomolded cooler (like a Yeti or similar) and fill it with ice—not just a few cubes—you’ve got maybe 4–6 hours before things start creeping past 40°F. A cheap foam cooler? Less than half