As with hypnosis conducted by a professional hypnotist, there are a lot of misconceptions about self-hypnosis. When I suggest that someone practice self-hypnosis, I get a lot of questions about the hypnotic state itself, the common question is: What if I don’t wake up from hypnosis? And the simple answer to that question is: You will always wake up from trance no matter how deep you go; the stories about people who couldn’t be woken from hypnosis and had to live like zombies are false.
Another common question regards the hypnotized person’s ability to respond to situations in the environment in case of emergencies. As you are less aware of the surroundings while you are in hypnosis, you should be able to respond to any emergency. When I conduct self-hypnosis, I always return immediately to consciousness if someone knocks on the door. So you are perfectly safe in case of a fire or something similar that needs your immediate attention.
The feeling of being hypnotized differ from person to person; I have described this in greater length as a response to a question about how it feels to be hypnotized. You are encouraged to read this response to eliminate any misconceptions about the hypnotic state of mind.