It is narrated from Sayyiduna Abu Hurairah (may Allah be pleased with him) that the Messenger of Allah (peace and blessings be upon him) said: "When it is hot, cool the prayer, for indeed the severity of heat is from the steam of Hell." And he mentioned: The Fire complained to its Lord, so Allah Almighty allowed it two breaths—one in the cold and one in the heat.
Hadith Referenceالسنن المأثورة / باب ما جاء في الصلاة على الراحلة / 120
Hadith Takhrijصحیح مسلم، المساجد ومواضع الصلاة، باب استحباب الابراد بالظهر في شدة الحر، رقم: 617