Food jars are the move, not thermoses.

If you want to keep hot food hot all morning without wrestling with a narrow-mouthed thermos, get a wide-mouth insulated food jar instead.

A classic thermos is great for coffee or soup, but it’s awkward when you’re trying to eat a real meal out of it. A food jar is the same vacuum insulation but with a wider opening, so you can comfortably eat rice, stew, pasta, or curries right from the jar. The Thermos Stainless King and Zojirushi food jars are the reliable names—they’ll keep things hot for 6–12 hours and basically last forever.

If you actually meant “no vacuum insulation at all,” then electric heated lunch boxes are an option, but they need an outlet and only warm food up—they don’t hold temperature. You’d be carrying two containers just to achieve what a food jar does in one. So if your goal is to open your lunch and still see steam, a wide-mouth vacuum jar is the answer. Call it whatever you want.

Future You deserves hot lunch, not lukewarm soup, and this is how you get it.