The Prophet ﷺ said regarding fever, "Cool it down with water, for it comes from the blazing heat of Hell."
حدثنا محمد بن جعفر حدثنا شعبة عن حبيب الأنصاري قال سمعت
عن النبي ﷺ أنه قال في الحمى أبردوها بالماء فإنها من فيح جهنم
Its isnad is daif due to the anonymity of Ibn Abu Bashir and his daughter, as al-Husayni said, though he was challenged on this in al-Taajil. Ibn Abu Bashir's name was Bashir, but this was not what was meant by Bashir. The hadith is sahih and was mentioned earlier at 17199.