This is the kind of insanity which is called acrophobia.
"Counsels and Maxims From The Essays Of Arthur Schopenhauer"
Arthur Schopenhauer
It is a dread, just as misophobia or claustrophobia or acrophobia or any of the other dreads that we discuss in the chapter on that subject.
"Psychotherapy"
James J. Walsh
Probably the commonest is acrophobia, so that the detailed consideration of it shows the indications for other dreads.
"Psychotherapy"
James J. Walsh