The first law of thermodynamics, the law of conservation of energy, states that energy cannot be created or destroyed. Instead, energy is simply recycled and converted from one form into another. The body contains both electrical and chemical energy. The fate of each form of energy in the body after death is identified below.
- When the heart stops pumping blood after death, energy is lost to the environment as heat. The body's temperature starts to decrease. On average, the body temperature decreases about 1.5 degrees Fahrenheit per hour after death. This is known as the ‘death chill’ or algor mortis. The process continues until the temperature of the dead body reaches equilibrium with the temperature of its environment.
- After a human dies, decomposers in the ground such as fungi and bacteria return the chemical energy that is stored in the biomolecules of the human’s body to the ecosystem. The matter from the biomolecules that are broken down by the decomposers are then used to fuel other living organisms.