I have been wearing wigs of natural, not artificial, hair for five years because my original hair entirely fell out. These wigs have temporary adhesives and they can be changed from time to time. People used to see me in this way and know that it is not my original hair. What is the Sharee'ah ruling on wearing such hair, wipe over it in wudhoo’ (ablution), and perform Hajj or ‘Umrah while wearing it?

All perfect praise be to Allah, the Lord of the worlds. I testify that there is none worthy of worship except Allah and that Muhammad, sallallaahu ‘alayhi wa sallam, is His slave and Messenger.

If you mean that you use natural hair of humans, then, according the opinion of the majority of the scholars, that is prohibited. The following is stated in Al-Mawsoo‘ah Al-Fiqhiyyah:

The majority of the Hanafi, Maliki and Shaafi‘i scholars are of the opinion that extending one's hair by using human hair, regardless of whether it belongs to a man, woman, mahram (permanently unmarriageable) person, husband, or whomsoever, is forbidden. They quoted the following Ahadeeth to support their opinion. Asma’ bint Abu Bakr reported that a woman came to the Prophet, sallallaahu ‘alayhi wa sallam, and asked him, "O Messenger of Allah, my daughter was afflicted by measles and her hair fell out. I have recently married her off, can I fix hair extensions to her hair?" He said, "Allah has cursed women who fix hair extensions as well as those who have hair extensions done." According to another narration, she said, "Her head's hair fell out and her husband wants to rush the consummation of marriage. Should I fix hair extension to her hair?" The Messenger of Allah, sallallaahu ‘alayhi wa sallam, forbade that to her.

It was narrated on the authority of Ibn ‘Umar that he said, "The Messenger of Allah, sallallaahu ‘alayhi wa sallam, cursed women who fix hair extensions as well as those who have hair extensions done, woman who practice tattooing, and those who have it done."

It was also narrated on the authority of ‘Abdur-Rahman ibn ‘Awf, that he heard Mu‘awiyah, on the pulpit, in the year when he made Hajj, as he took a bunch of hair that was in the hand of a guard and said, "O people of Al-Madeenah! Where are your scholars? I heard the Messenger of Allah, sallallaahu ‘alayhi wa sallam, forbid such things and say, 'The Children of Israel were destroyed when their women used such things.'" It is also forbidden that humans' hair and other parts are utilized in any way, given its honor. Rather, their hair, nails and other parts should be buried.

Forbiddance is more emphasized if this action is done by a man as he can wear a hat or turban instead of a wig. Even, if he displays himself bald, it is not considered a defect, which is not the case with women.

Wiping over this hair during wudhoo’ is invalid because the obligation is to wipe over the head; the artificial hair or the wig is not part of the head.

Performing Hajj or ‘Umrah while one is wearing a wig is valid. However, if the one doing so is male, then he has violated one of the restrictions of Ihram (ritual state of consecration) by covering his head while he in such a state. This violation makes it incumbent upon him to offer a fidyah (slaughter a sheep in Makkah and give it to the needy who live there, fast three days, or give three saa‘s [plural of saa‘: a volumetric measure] of food to six needy persons in Makkah by giving half a saa‘ to each one of them). It is recommended, but not obligatory, for a bald performer of Hajj or ‘Umrah to pass the razor over his head when he wants to end his state of Ihram.

Allah knows best.