Silsilat al-Ahadith al-Sahihah

It is narrated from Sayyiduna Miqdad (may Allah be pleased with him) that the Messenger of Allah (peace and blessings of Allah be upon him) said: "When the Day of Resurrection comes, the sun will be brought so close to the people that it will be at a distance of one or two miles from them. The sun (its heat) will melt them, and they will be submerged in sweat according to their deeds. Some will have sweat up to their ankles, some up to their knees, some up to their waists, and some up to their mouths." Then he (peace and blessings of Allah be upon him) pointed towards his mouth, meaning it will reach up to his mouth.