Musnad Abu Ya'la al-Mawsili 111:120

Abu Khaythama narrated to us, Affan narrated to us, Hammam narrated to us, Abu Jamra informed us that he used to sit with Ibn Abbas, and he (Ibn Abbas) would push the people away from him. He said: "I was detained from him for some days, so he said to me, 'What kept you back?' I said, 'The fever.' He said, 'The Messenger of Allah (ﷺ) said: "Indeed, the fever is from the scorching heat of Hell, so extinguish it from yourselves with Zamzam water."'"