There is fundamental assumption that all our experiences are otherwise trapped in body. The classical mind body dualism debate. Hindu writings are quite extensive on that.
Let us consider when we are thinking about our illnesses our body or our looks, is the experience part our physical existence or beyond. If we believe that our consciousness are outside physical realm of our existence we are having out of body experiences all th time.
going away from the phisophical undertone of the issue and coming directly to question. There are several different evidences that can be equated to such experiences most authentic seeming ones are the people who have narrated their |Near deathexperiences" . There people were deep coma and normal conventional sense of consiousness was not availble to them, yet they experienced things ( strangely very similar to each other.
Anyway I hope you are not watching too much of Raaz pichhle Janam ka...