Bismillah Walhamdulillah Was Salaatu Was Salaam ‘ala Rasulillah Narrated Abu Jamra Ad-Dabi (Radi-Allahu ‘anhu):

I used to sit with Ibn ‘Abbas in Makkah. Once I had a fever and he said (to me), “Cool your fever with Zam-zam water, for Allah’s Apostle (Sallallahu ‘Alaihi Wa Sallam) said: ‘It, (the Fever) is from the heat of the (Hell) Fire; so, cool it with water (or Zam-zam water).”

Bukhari Vol. 4 : No. 483