Clinical death happens when brain is intact
If the brain was intact during death a person goes into a phase of clinical death where the heart stops but the brain still works.
After clinical death occurs biological death happens if the person wasn’t saved. During biological death brain cells die.
Survivors of clinical death felt no pain
According to some people who survived clinical death, they felt no pain at the time of going unconscious.
After death brain activity
Scientists noticed that after death the brain remains active for some time
Some survivors of clinical death reported seeing a tunnel vision. Scientists believe this tunnel vision could be caused by the restricted flow of blood to the eye.
Dream like state
According to a Quora thread, the brain releases endorphin LSD which is a substance that makes a person enter a dream-like a state where the dream feels so real.
Stories of clinical death survivors
Many survivors of clinical death told stories where they have come out of their bodies and saw themselves on their death bed. Some scientists believe that those stories are the result of the dream-like state the brain enters. (See Study: Consciousness after clinical death)
A slipping away feeling
Some survivors have described the moment of death as a moment where they slip away into a void.
A short nap
According to a person who survived clinical death twice, dying is like a blank state or a short nap with no dreams or consciousness.
It felt like a long time
Many of those who survived minutes of clinical death said that it felt like they were gone for so long and not just a few minutes.
Bright lights are seen by 8%
According to a nurse who witnessed many near death experiences, the bright light people see is common among 8% of people and it happens due to flooding of phosphenes from the Pineal gland. (See What does it feel like to drown?)
What does it feel like to die?
What Does It Feel Like to Die? Inspiring New Insights Into the Experience of Dying!