Is it permissible for a woman to remove her hijab if she suffers from a skin disease in the head and ear, and the area's temperature rises, and doctors advise removing the hijab to alleviate the condition?

It is obligatory for a woman to cover her head and her entire body from non-mahram (definition) men, based on the Almighty's saying: "O Prophet, tell your wives and your daughters and the women of the believers to bring down over themselves [part] of their outer garments. That is more suitable that they will be known and not be abused. And ever is Allah Forgiving and Merciful." So, the hijab (definition) is a firm obligation. If there is harm from covering part of the head or ear, she must stay at home. If she is forced to go out, she should find a way to reduce the friction of her hijab against her head, while being careful to maintain her hijab, which is the symbol of her modesty.