Aishah (May Allah be pleased with her) reported: I heard Messenger of Allah (sallallaahu ’alayhi wa sallam) saying, “The people will be assembled on the Day of Resurrection barefooted, naked and uncircumcised.” I said, “O Messenger of Allah! Will the men and the women be together on that Day; looking at one another?” Upon this, the Messenger of Allah (sallallaahu ’alayhi wa sallam) said, “O Aishah, the matter will be too serious for them to look at one another”.
[Al-Bukhari and Muslim].
This Hadith mentions the horrors and torments of the Day of Resurrection. It is that a Muslim should never be unmindful of the preparations for the Hereafter nor should he ever lose sight of the fact that he has to appear before Allah on the Day of Resurrection and account for all his actions. In order to save himself from the humiliation on that Day, he should lead a life of Faith and fear of Allah. Those who do not do so and lead a life free from fear of Allah and torments of the Hereafter will have no hesitation in disobeying Allah, which will inevitably lead them to humiliation, disgrace and heavy punishment in the Hereafter.
[Riyad as-Saliheen, Book of Miscellany, Chapter 50, Hadith 411 – slightly modified without distorting the main idea]