It is narrated from Abu Huraira (may Allah be pleased with him) that he reports the Messenger of Allah (peace and blessings be upon him) said: "When the heat becomes intense, perform the prayer at a cooler time, for the severity of heat is from the boiling of the Hellfire." And he said: "The Hellfire complained to its Lord and said: (Due to the intensity of the fire) some parts of me have consumed others. So Allah, the Exalted, allowed it two breaths: one breath in the winter and one breath in the summer. Thus, the extreme heat and extreme cold that you experience are because of this."
Hadith Referenceمسند الإمام الشافعي / كتاب الصلاة / 134
Hadith Takhrijاخرجه البخاري: مواقيت الصلاة، باب الابراد بالظهر في شدة الحر (536) ومسلم، المساجد، باب استحباب الابراد بالظهر في شدة الحر لمن يمضى الى جماعة (615) .