I had an old, ratty denim Dickies coat with thick insulation that probably weighed six or seven pounds. I’d throw it over a few water bottles on the floor or the seat, and they’d still be cool when the ones exposed in the backseat were warm, almost hot. Seriously, I had better luck with that coat than I had with coolers without ice.
I used to keep a white towel over the 24 packs of water I kept in my back seat, that really does work. 100°F outside, water is still a crisp 72°
I had an old, ratty denim Dickies coat with thick insulation that probably weighed six or seven pounds. I’d throw it over a few water bottles on the floor or the seat, and they’d still be cool when the ones exposed in the backseat were warm, almost hot. Seriously, I had better luck with that coat than I had with coolers without ice.