It is narrated from Sayyidah Aisha (may Allah be pleased with her) that the Prophet (peace and blessings be upon him) said: "Fever is from the steam of Hell, so cool it with water."
Hadith Referenceمسند الشهاب / 61
Hadith Gradingمحدثین:إسناده صحيح
Hadith Takhrij«إسناده صحيح ، أخرجه البخاري 3263، مسلم : 2210، ترمذي : 2074، ابن ماجه : 3471»
Brief Explanation
Explanation – Fever is from the steam of Hellfire. The best meaning of this statement of the Messenger (sallallahu alayhi wa sallam) is known only to Allah Ta’ala. However, some scholars say that its meaning is that through fever, remember Hellfire, or just as the joys and comforts of this world have a certain connection with the blessings of Paradise, similarly, pain and sorrow also have a connection with Hellfire.
“Cool the fever with water.” Some physicians say that in every case of fever, when the heat increases greatly, there are two ways to treat it with water: The first method is to apply cold externally with ice or water, such as placing compresses on the body, so that the temperature comes down. The second method of treatment is to give the patient small amounts of water to drink repeatedly, so that all the bodily organs, especially the kidneys, are engaged in their respective functions, doing something for the body’s vitality. (For details, see: Tibb an-Nabawi by Ibn Qayyim, p. 44)