Nocturnal panic is a type of parasomnia that manifests in a sudden and unexpected manner while sleeping. The afflicted person wakes abruptly, feeling anxiety, terror, and an intense sense of dread.
It usually occurs with the individual in a state of rapid eye movement (REM) sleep, with dreams that are either frightening or extremely stressful.

Example:
During the first half of the night, a kid might wake and start screaming and crying while ignoring their parents calling for them.
While this happens, the kid might have their eyes wide open but they don't see anything.
If you try to help them they can be more scared while also manifesting extreme sweating, rigid muscles, and tachycardia.
While it might seem that the kid is awake, they are actually in their third and fourth phase of non-rem sleep.
After the crisis, they will relax and keep on sleeping without remembering what happened.