Language:
كتاب مواقيت الصلاة
9  
Times of the Prayers
(9)
Chapter: In severe heat, offer Zuhr prayers when it becomes (a bit) cooler
(9)
باب الإِبْرَادِ بِالظُّهْرِ فِي شِدَّةِ الْحَرِّ
Sahih al-Bukhari 536, 537

Narrated Abu Huraira:

The Prophet (ﷺ) said, "In very hot weather delay the Zuhr prayer till it becomes (a bit) cooler because the severity of heat is from the raging of the Hell-fire. The Hell-fire of Hell complained to its Lord saying: O Lord! My parts are eating (destroying) one another. So Allah allowed it to take two breaths, one in the winter and the other in the summer. The breath in the summer is at the time when you feel the severest heat and the breath in the winter is at the time when you feel the severest cold."

حَدَّثَنَا عَلِيُّ بْنُ عَبْدِ اللَّهِ، قَالَ حَدَّثَنَا سُفْيَانُ، قَالَ حَفِظْنَاهُ مِنَ الزُّهْرِيِّ عَنْ سَعِيدِ بْنِ الْمُسَيَّبِ، عَنْ أَبِي هُرَيْرَةَ، عَنِ النَّبِيِّ صلى الله عليه وسلم قَالَ ‏"‏ إِذَا اشْتَدَّ الْحَرُّ فَأَبْرِدُوا بِالصَّلاَةِ، فَإِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ ‏"‏‏.‏ ‏"‏ وَاشْتَكَتِ النَّارُ إِلَى رَبِّهَا فَقَالَتْ يَا رَبِّ أَكَلَ بَعْضِي بَعْضًا‏.‏ فَأَذِنَ لَهَا بِنَفَسَيْنِ نَفَسٍ فِي الشِّتَاءِ، وَنَفَسٍ فِي الصَّيْفِ، فَهُوَ أَشَدُّ مَا تَجِدُونَ مِنَ الْحَرِّ، وَأَشَدُّ مَا تَجِدُونَ مِنَ الزَّمْهَرِيرِ ‏"‏‏.‏
Reference : Sahih al-Bukhari 536, 537
In-book reference : Book 9, Hadith 14
USC-MSA web (English) reference : Vol. 1, Book 10, Hadith 512
  (deprecated numbering scheme)