well a polystyrene cup conducts heat so that is how it keeps your drink warm
sweat
No. It would have to be in a thermos to keep it warm.
yes it would keep your food warm,they are used worldwide in fast food outlets and caffes to keep cooked food warm.
A food warming tray usually just gets hot enough to keep food that is already warm, warm. A crockpot on the other hand will keep food warm and get hot enough to cook it.
If you put in warm food it will keep it warm without cooking it further.
A thermos bottle (Actually a thermos container, which has a wider lid) will work.
yes :)
Usually food it packed in Styrofoam to keep it cold (or warm)
Keep warm near a fireplace, and maybe try to eat some hot or warm food.
keep it nice and warm and put it in a little container then put so water in it
To keep warm or to cook food.
Because being warm blooded, they need food to keep themselves warm.