Nigeria, Dec. 15 -- The human body is not a sealed container. It is an open system, more like a small, steady fire than a closed box. Every day, energy flows in through the food we eat and flows out as heat. This constant movement of energy is not optional but how life is sustained. Health therefore depends on keeping this flow moving. When the body turns food into energy, heat is always produced. Roughly 40 percent of that energy is captured as ATP to power muscles and organs, while the rest is released as heat. Some of this heat helps keep us warm, but whatever is not needed must be released through the skin, breathing, and circulation. This happens automatically, every minute of the day. The fire is always burning, and the body is alwa...