Answer:
Cold head and feet; round as a ball; always turning around myself.
Poor people have it. Rich people need it. If you eat it you die. What is it?
What kind of room has no doors or windows?
I go inside boots and outside shoes. What am I?
I am always around you but often forgotten. I am pure and clean most time but occasionally rotten.
Give it food and it will live, give it water and it will die.