Usually, a hypnotized person forgets to blink, giving the impression of being out of breath. However, the subject is in a hyperactive mental state, activating areas of the brain that normally do not show as much activity. One less.
When an individual is hypnotized, there is a region of the brain that has its activity reduced, precisely the one related to the spatial perception and that we have of ourselves, in addition to our episodic memory. This causes the hypnotized person to concentrate intensely on something created by their own imagination - or that has been suggested - but not as part of what is being imagined. Hypnotized people lose the ability to remember what they would normally do in certain situations, while the ability to think about a variety of imaginary options increases.
This explains why people in a hypnotic state end up behaving completely differently from normal, remaining calm in situations in which they would feel terrified, for example.