It is narrated from Sayyiduna Uqbah bin Amir al-Juhani (may Allah be pleased with him) that he heard the Messenger of Allah (peace and blessings be upon him) saying: "The sun will draw near to the earth and people will be drenched in sweat. The sweat of some people will reach their ankles, of some to the middle of the shin, of some to their knees, of some to the buttocks, of some to the waist, of some to their shoulders, of some to their neck, and of some to the middle of the mouth" - and he (peace and blessings be upon him) gestured with his hand and showed it by bringing it to his mouth; I saw the Messenger of Allah (peace and blessings be upon him) (doing) it like this - "and some people will be such that their sweat will cover them completely." And he (peace and blessings be upon him) gestured with his hand, passing it over his head without the hand touching the head, to the right and the left. This hadith has a sahih (authentic) chain, but the two Shaykhs (Bukhari and Muslim) did not record it.