GEOLOGY

Detailed explanation-1: -To keep hot food hot, pour boiling water into the thermos, close the lid, and let stand 10 minutes. Meanwhile, heat the food until piping hot (hotter than you would normally serve it). Dump the water, put the food in the thermos, and seal the lid. Your food should stay warm and is safe to eat within 5 hours.

Detailed explanation-2: -What should I put in my thermos? Use a thermos to pack foods that have some sauce or liquid like stew and soup. A thermos can only keep food hot or cold if it has some sauce or liquid. Use a thermos to pack beverages that need to be kept hot like coffee or tea or cold like milk or 100% juice.