When a human dies, the body doesn’t shut down all at once. Each organ has its own timeline for losing function, depending on its oxygen and energy requirements. The brain is the first to fail, with cells dying within 4–7 minutes after oxygen stops, marking brain death. The heart and lungs usually follow within minutes, but in hospital settings, machines can temporarily sustain them, allowing up to 4–6 hours for possible transplant.

Mid-range organs like the liver, pancreas, and intestines begin to deteriorate within 8–18 hours unless quickly preserved in cold storage. Kidneys and corneas are more resilient, lasting up to 36 hours and 14 days respectively if properly stored. Soft tissues like skin and bones can remain viable for days or even years.

This orderly shutdown is critical for organ donation. Timing is everything: transplant teams must act quickly to ensure organs are still functional. Understanding how and when organs stop working not only provides insight into the human body but also saves lives by maximizing the chances of successful transplantation.