Keep a barrier between produce and ice

The trick is to keep a barrier between your produce and the ice. Ice is sitting at 32°F, and if your veggies are touching it directly, they’ll freeze, get waterlogged, and turn into sad mush — that’s contact freeze, not true frostbite.

Lay down a folded towel, a piece of cardboard, or even a newspaper layer on top of the ice, then put the vegetables and fruit on that. If you have a plastic milk crate or mesh basket, even better — it gets them off the bottom entirely and lets cold air circulate without the wet contact.

Also, drain the melted water when you can. Cold water transfers heat away from produce way faster than cold air, so vegetables sitting in a puddle of ice water will chill too hard even without touching the ice. If you’re using loose ice, keep the drain plug open or pour off the water periodically.

And if you’re packing for a long trip, frozen water bottles work better than loose ice anyway — they freeze produce less because the contact area is smaller and they don’t create meltwater. But you still want a buffer.

It’s not fancy. A crumpled cardboard box from the grocery store works great and keeps your salad crisp for days.