Sahih al-Bukhari 3262
صحيح البخاري#3262SahihNarrated Rafi` bin Khadij:I heard the Prophet (ﷺ) saying, "Fever is from the heat of the (Hell) Fire; so cool it with water
Scholarly Authentication
We show the most cautious grade (weakest-wins) as the overall label. Individual scholars graded it as follows:
Every narration in Sahih al-Bukhari is accepted as Sahih (authentic) by the established status of the book.
In-book reference: 59:72