Get a vacuum jar, not a heated lunch box

A good vacuum-insulated food jar is the best lunch box for keeping food warm until noon, as long as you preheat it. Heated lunch boxes are a gimmick unless you have a desk outlet.

The trick is physics, not magic. A Thermos, Zojirushi, or Stanley food jar has double steel walls with a vacuum between them. Fill the jar with boiling water for five minutes before you add your food. Dump the water, dry it quickly, then pack your piping-hot food. Seal it, and it will still be hot at lunchtime — not lukewarm, actually hot.

Wide-mouth jars are for solids like pasta, rice, and braised meat. Narrow ones are for soups and stews. Zojirushi makes the best seals, but Stanley’s are nearly indestructible. Any of them beats an electric box that needs a plug and might melt your leftover lasagna.

One more thing: warm the food before sealing. If it goes in warm, it comes out cold.

Future You deserves a hot lunch.