A thermos and an ice pack solve this.

Packing hot and cold together works fine if you use the right containers and stop worrying about them touching.

The hot stuff goes in a thermos or insulated food jar. Not a regular plastic container — a real vacuum-insulated one. Preheat it with boiling water for five minutes, dump the water, then add the hot food. That alone keeps soup, pasta, or curry hot until noon.

The cold stuff just needs a decent insulated bag and one freezer pack. The bag does the work, not the arrangement. You can toss a yogurt next to a thermos of chili and neither will budge much because the thermos holds its own temperature and the ice pack holds the other side.

One thing: don’t put the hot container directly on top of a salad or anything delicate. The heat transfers through the bottom even with a good thermos. Slide a folded napkin, a small cutting board, or an apple between them. That’s it. The whole “hot and cold can’t share a bag” thing is a myth — they just need their own insulated zone.

You’re not trying to make the whole bag one temperature. You’re trying to keep each item its own temperature.