Sunan Ibn Majah, Book 31, Hadith 3600 (In-Book) ⓘ
It was narrated from ‘Aishah that the Prophet said: “Fever is from the heat of the Hell-fire, so cool it down with water.”
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدُ اللَّهِ بْنُ نُمَيْرٍ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ أَبِيهِ، عَنْ عَائِشَةَ، أَنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ قَالَ " إِنَّ الْحُمَّى مِنْ فَيْحِ جَهَنَّمَ فَابْرُدُوهَا بِالْمَاءِ " .
also referenced under: Hadith 3471 (Reference) & Volume 4, Book 31, Hadith 3471 (DarusSalam)