Frozen jugs are better than ice packs for coolers.

Yes, frozen water jugs are the best alternative to traditional ice. They last longer, cost less, and won’t leave your food swimming.

Ice packs are fine for a small lunch bag, but for a real cooler, the problem is surface area. A bunch of small ice packs melt faster because they’re exposed to air on all sides. A half-gallon frozen jug (milk jug, soda bottle) has less surface area per volume, so it stays frozen longer. Plus it won’t leak slime if it cracks—it’s just water. And when it’s melted, you’ve got cold drinking water.

Dry ice is overkill unless you’re keeping stuff frozen for days. Gel packs are expensive and lose their chill fast in hot weather. The cheap solution: fill empty containers with tap water, freeze them, throw them in. Done.

If you’re not camping for a week, just buy a bag of ice. But for a day trip or overnight, frozen jugs win.