Sahih Muslim , Book 39, Hadith 111 (In-Book) ⓘ

Asma' reported that a woman running high fever was brought to her. She asked water to be brought and then sprinkled it in the opening of a shirt at the uppermost part of the chest and said that Allah's Messenger had said: Cool (the fever) with water. for it is because of the vehemence of the beat of Hell.

وَحَدَّثَنَا أَبُو بَكْرِ بْنُ أَبِي شَيْبَةَ، حَدَّثَنَا عَبْدَةُ بْنُ سُلَيْمَانَ، عَنْ هِشَامٍ، عَنْ فَاطِمَةَ، عَنْ أَسْمَاءَ، أَنَّهَا كَانَتْ تُؤْتَى بِالْمَرْأَةِ الْمَوْعُوكَةِ فَتَدْعُو بِالْمَاءِ فَتَصُبُّهُ فِي جَيْبِهَا وَتَقُولُ إِنَّ رَسُولَ اللَّهِ صلى الله عليه وسلم قَالَ ‏"‏ ابْرُدُوهَا بِالْمَاءِ ‏"‏ ‏.‏ وَقَالَ ‏"‏ إِنَّهَا مِنْ فَيْحِ جَهَنَّمَ ‏"‏ ‏.‏