Physical Changes
Within the first 24 hours after death, the body begins to undergo physical changes. Rigor mortis, or stiffness of the limbs, begins to set in, starting at the head and moving down to the toes. The body may become discolored, depending on the individual's skin tone; pale or ashen in lighter skin tones, and darker in darker skin tones. These physical changes will continue for several days, and in some cases, weeks.
Cooling of the Body
The body will begin to cool rapidly after death, as the body is no longer metabolizing and producing heat. The rate of cooling is determined by environmental factors, such as the temperature of the surrounding air, and the body's position.
Organ Failure
Within the first 24 hours after death, organ failure will begin to set in as cells become deprived of the oxygen and nutrients they need to function. The kidneys and liver will begin to fail, and the heart will eventually stop beating.
Postmortem Interval
The postmortem interval is the time between death and the discovery of the body. During this time, the body will continue to undergo physical changes, and will be affected by environmental factors such as temperature, humidity, and insects. In some cases, the postmortem interval can be used to estimate the time of death.