Sunan Ibn Majah, Volume 4, Book 31, Hadith 3474 (DarusSalam) ⓘ
It was narrated from Asma’ bint Abu Bakr that a woman suffering from fever would be brought to her, and she would call for water and pour it onto the neck of her garment. She said: The Prophet said: “Cool it down with water,” and he said: “It is from the heat of Hell-fire.”
حَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدَةُ بْنُ سُلَيْمَانَ، عَنْ هِشَامِ بْنِ عُرْوَةَ، عَنْ فَاطِمَةَ بِنْتِ الْمُنْذِرِ، عَنْ أَسْمَاءَ بِنْتِ أَبِي بَكْرٍ، أَنَّهَا كَانَتْ تُؤْتَى بِالْمَرْأَةِ الْمَوْعُوكَةِ فَتَدْعُو بِالْمَاءِ فَتَصُبُّهُ فِي جَيْبِهَا وَتَقُولُ إِنَّ النَّبِيَّ ـ صلى الله عليه وسلم ـ قَالَ " ابْرُدُوهَا بِالْمَاءِ " . وَقَالَ " إِنَّهَا مِنْ فَيْحِ جَهَنَّمَ " .
also referenced under: Hadith 3474 (Reference) & Book 31, Hadith 3603 (In-Book)