The heart is an organ that pumps blood through the circulatory system. Blood provides the body with oxygen and nutrients and assists in the removal of metabolic wastes. Metabolism is the process in which food is turned into energy. This system determines which substances are nutritious and which are poisonous. The metabolic speed rate influences a creature's hunger rate.
Hearts can occasionally be purchased from exotic goods traders. A free heart is produced after installing a prosthetic heart or bionic heart in a colonist or prisoner. A heart can also be harvested from a prisoner, killing them in the process and incurring serious mood penalties for the entire colony.