A common fallacy is that people lose all control under hypnosis and can be made to react as the hypnotic dictates. Even at the deeper levels of hypnosis dictates. Even at the deeper levels of hypnosis required, for example, in the suppression of severe pain, as one part of the mind becomes relaxed and inattentive, another part becomes increasingly aware. In fact, awareness reaches a level many times greater than that experienced in the state we call normal awakening consciousness. This leads many people to the mistaken belief that they are not actually hypnosis expands the levels of ordinary consciousness, widening perception and deepening your power of introspection, it does not cause you to lose consciousness.
If the circumstances are appropriate, you may choose to drift in to a light hypnotic sleep. This is entirely acceptable because your subconscious mind never sleeps and you will continue to absorb the recorded or spoken messages, awakening fully refreshed at whatever time you have chosen.
A simple hypnotic technique is used to enable you to return to normal awakening consciousness at any predetermined time. However in the event of any form of emergency, the enhanced awareness ensures that you will respond instantly in a calm, effective and confident manner. Your subconscious mind is deeply concerned with survival and invariably acts to ensure it, as you will have experienced in driving when your conscious mind may have drifted to the extent that you fail to recall having passed a familiar landmark.