Answer: This tradition was born in ancient times when people living in Mesopotamia, ancient Israel and Egypt covered their heads to protect themselves from the sun. And even today, the Bedouins cover their heads as protection from the heat.
As for the Kabbalists, in no way do they connect themselves or their Kabbalistic attainments with external rituals. This is unnecessary for both people and the Creator.
From the Kabbalah Lesson in Russian 11/12/17