Is it permissible for a woman to tie her head covering to secure the hijab during Hajj, and is it permissible for a male in a state of ihram to tie or knot his izar?

It is permissible for a woman in a state of ihram for Hajj or Umrah to cover her entire body except for her face and palms, based on the Prophet's (peace and blessings be upon him) saying: "The woman in ihram should not wear a niqab nor gloves." She should cover her face from non-mahram men without using a niqab. It is also permissible for a woman in ihram to tie her head covering to secure her hijab, especially if she fears revealing her awrah in front of non-mahram men. There is no harm for a man in tying his izar (waist wrapper).