There's a scientific law which states that energy cannot be destroyed and we know that consciousness is a form of energy.
The naturalist, however, would have us believe that self-awareness expires at the moment of physical death.
There are even certain followers of the Bible who believe this heresy, what with the doctrines of soul-sleep and annihilationism being rather patently unbiblical. These ones opine that such a teaching of an immortal soul conflicts with the idea of a resurrection. What need would there be for one to be resurrected if they are truly dead?, they question. (They point to the passage at Ecclesiastes 9:5-6 as scriptural backing for this belief.)
Solomon B. Shaw's Dying Testimonies Of Saved And Unsaved is a classic work within the literature of after-death studies. This deeply absorbing read was first published in 1898, and yet is not about NDEs but their precedent anomalies, if you will: namely, deathbed visions. The book is a collection of testimonies of what various people have both seen and heard while in the final stages of dying.
One reads of hardened sinners and atheists, expressing their regrets at the lives they led and offering confessions and recantations, respectively. One also reads of witnesses to agape mouths and wide-eyed, transfixed stares of those who supposedly met their unpleasant, eternal fate, instantaneously, upon their transition from a physical to a spiritual body.
In modern times, NDE researchers in general tend to dismiss negative accounts in favor of the Omega philosophy where each and everyone receives a free pass to the pearly gates. Interestingly, Christ talked more about the fate of those on their destructive paths than he did of the afterlife of those on the straight-and-narrow road which leads to paradise.
There are over 200 testimonies contained in this book, some of which are faith-strengthening and others of which may have one immediately taking up exercise and a healthy diet in order to prolong the inevitable.
During the time these testimonies were recorded and collected, it was quite common for people, the aged, to pass away in their bed-chambers, away from the (most likely dismissive) ears of hospital doctors and nurses.