For hot food, you want a thermos, not a lunch box

If you want food to stay hot until noon, skip the lunch bag and buy a vacuum-insulated food jar — a thermos-style container, not a box.

Soft lunch bags are for cold stuff. That shiny foil lining and the ice packs do almost nothing to hold heat in. For hot food you need double-wall vacuum insulation, which traps heat between two steel walls. That’s a thermos. That’s the whole game.

The trusty names are Zojirushi and Thermos. Zojirushi is the fancy one — it’ll keep soup or curry genuinely hot for 8 hours. Thermos makes cheaper stainless steel food jars that work fine. Avoid anything with a plastic interior; it holds heat worse and tastes funny.

One trick: pre-heat the jar. Fill it with boiling water, close it, wait five minutes, dump it, then put your food in. Fill it as full as you can — empty space means heat loss. And don’t open the lid to “check” if it’s still warm. Every time you open it, you let the heat out.

Cold curry at 1pm is a sad moment. Don’t do that to yourself.