For backpacks and mini-fridges, go with bento boxes, not coolers.

A slim bento-style container is the answer, not a bulky insulated cooler. It slides flat into a backpack pocket and into a compact office fridge without a fight.

Most standard backpacks have a depth of about six inches, and mini-fridge shelves are rarely more than twelve inches wide. Round or tall lunch boxes waste that space. A rectangular bento around 10 by 7 by 2 inches uses every bit of it. Brands like Bentgo or a simple glass Snapware set work perfectly. They have compartments, so your soup isn’t touching your sandwich, and they disappear into a fridge shelf.

Soft-sided lunch bags are okay, but you usually have to empty them to fit in the fridge. That’s annoying. A hard-sided bento goes straight from backpack to cold shelf, no transfer needed. If you want to keep things cold, just toss a thin ice pack on top inside the container.

It’s the lunch equivalent of packing your bag properly instead of shoving a beach cooler sideways. Your future self won’t have to wrestle the Tupperware avalanche.