Sayyiduna Salamah bin al-Akwa' (may Allah be pleased with him) narrates: We visited a man suffering from fever along with the Messenger of Allah (peace and blessings be upon him), and I said: O Messenger of Allah, I have never seen more intense heat than this. He (peace and blessings be upon him) said: "Shall I not tell you of the most intense heat on the Day of Resurrection? It belongs to these two men who are coming, riding" - he (peace and blessings be upon him) said this at that time about two men among his companions.
Hadith Referenceالمعجم الكبير للطبراني / باب السين / 6221