Ice pack and a sealed container. That's the whole trick.

The safest setup is an insulated lunch bag, a quality ice pack, and a sealed container that keeps the sushi from touching the ice directly.

Raw fish needs to stay under 40°F, and the clock starts ticking once it leaves the fridge. If you’re packing sushi in the morning and eating it at lunch, that’s a few hours, so a decent insulated bag with a frozen ice pack is usually enough. A cheap fabric lunch tote with no insulation won’t cut it, and that flimsy paper box from the sushi place won’t hold temperature either.

Put the sushi in a small airtight container — glass or plastic works — and place the ice pack underneath it or on top of it. The goal is to keep everything cold, not to soak the rice. If you can, put the whole thing in the fridge when you get to work. If you can’t, eat it within four hours of packing. After that, raw fish gets sketchy.

One more thing: don’t prep sushi the night before and expect it to be great. It’ll be safe if chilled properly, but soggy rice and cold fish is a sad lunch. Pack it fresh in the morning.