Muwatta Malik 1727
موطأ مالك#1727SahihMalik related to me from Nafi from Ibn Umar that the Messenger of Allah, may Allah bless him and grant him peace, said, "Fever is from the vehemence of the heat of Jahannam, so put it out with water
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Salim al-HilaliSahih
In-book reference: 50:17