The Book of Prayers (Kitab Al-Salat)

Muslim :: Book 4 : Hadith 1288

Hammam b. Munabbih reported: This is what Abu Huraira narrated to us from the Holy Prophet and he transmitted some ahadith-one of them was that the Messenger of Allah (may peace be upon him) said: Let the heat become less severe before prayer, for the intensity of heat is from the exhalation of Hell.

Source materials are from the University of Southern California MSA site
Hadith eBooks converted from Imaan Star