Yahya related to me from Malik from Hisham ibn Urwa from his father 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 cool it with water." Malik related to me from Nafi from Ibn Umar (RA) 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."