The answer may surprise you.
If you were to see “Joe” in deep hypnosis or trance he would look as if he is asleep or unconscious. But, that is not the case. A hypnotized person is aware of and responsive to their environment.
Trance can be defined as a state of single minded focus or narrowed awareness of attention on a single idea. The sounds and sights may recede from a hypnotized person’s conscious awareness, like the sensations of the back of your neck as you are reading this, but those sensations are there none the less.
In the case of a fire alarm, experience has shown that Joe would get up and calmly walk to the nearest exit in a way that is more efficient and direct than if he had been in the normal waking state. The unconscious mind is in charge while someone is in hypnosis, and will protect the person from any harm or potential danger in the same single minded manner that it responds to the suggestions of the hypnotist.