A character exhibits an extreme or irrational fear of heights.

Examples:
In "Vertigo" (1958), detective John Ferguson is left hanging from a gutter watching a colleague tumble to his death, after a perilous rooftop pursuit. The experience leaves him with such an extreme fear of heights that he can no longer continue in his job.

Aliases:
acrophobia

References:
https://en.wikipedia.org/wiki/Acrophobia