I find NDEs fascinating to consider. These experiences have been documented over many years and are defined as a common set of events experienced by people when seriously ill or close to death. Irrespective of people’s faith persuasion or lack of, they have a set of common elements:
Three quarters of those having these experiences, feel an out of body feeling; the senses are more heightened than normal and they experience intense emotions, love and peace. Two thirds of people see or encounter brilliant colours and lights with a different sense of time or space and more than half encounter other people, friends or relatives; receive special knowledge and encounter heavenly places and know they must return to their earthly bodies. One quarter to a third passed through a tunnel or a barrier and experienced a review of their lives. 
This is amazing stuff and many people return with the knowledge of God, heaven and the need to tell others. There is even an organisation set up now to investigate NDEs, the international Association of Near-Death Studies or IANDS, who scientifically investigate these occurrences.
Apparently one in 10 people have experienced a NDE. The reputable medical journal, the Lancet, has reported an account of a patient who had a cardiac arrest and saw a nurse place his dentures in a drawer whilst he was in a comatose state and not breathing (but was later resuscitated). A week later, now conscious, they were able to find his dentures by the patient recognising the nurse and reminding her where she had placed them. He had watched all of that from above, whilst unconscious and without any vital signs.