All perfect praise be to Allaah, The Lord of the Worlds. I testify that there is none worthy of worship except Allaah, and that Muhammad, sallallaahu ‘alayhi wa sallam, is His Slave and Messenger.
It has already been confirmed from the Prophet, sallallaahu ‘alayhi wa sallam, that the people would be raised on the Day of Judgment barefooted, naked and uncircumcised. For further information, refer to Fataawa 87991 and 85503.
There is also a narration indicating that afterwards the people would be dressed. It is narrated on the authority of both Ibn ‘Abbaas and ‘Aa’ishah that the Prophet, sallallaahu ‘alayhi wa sallam, said: “No doubt, you would be gathered (on the day of Judgment) barefooted, naked and uncircumcised.” Then, he recited (what means): {As We began the first creation, We will repeat it. [That is] a promise binding upon Us. Indeed, We will do it.}[Quran 21:104] “The first to be dressed on the Day of Judgment will be Ibraaheem (Abraham)...” [Al-Bukhari]
In his commentary on Riyaadh As-Saaliheen, Shaykh Ibn ‘Uthaymeen said: “This Hadeeth proves that people would be dressed after their being raised barefooted, naked and uncircumcised. But how would they be dressed? We do not know… Only Allaah Knows how that will be done."
On the other hand, after men and women are raised barefooted and naked, they would be gathered in one place seeing each other, but the terror of the Day of Judgment would be too difficult on them to be mindful of this. That is confirmed in the previous Hadeeth, in which ‘Aa’ishah said: I said: “O Messenger of Allaah! Will the men and the women look at each other?" He said: “The situation will be too hard for them to pay attention to that." [Al-Bukhari] According to another narration, ‘Aa’ishah said: I said: “O Messenger of Allaah! What about the private parts (of men and women)?” He answered (reciting the verse which means): “{For every man, that Day, will be a matter adequate for him.}[Quran 80:37]” [Al-Haakim and An-Nasaa’i]
As for the claim that women on that day would cover their private parts with their long hair, it is groundless.
Allaah Knows best.