We were in the company of the Prophet ﷺ on a journey and the Mu'adh-dhin wanted to pronounce the Adhan for the (Zuhr) prayer. The Prophet ﷺ said to him, "Let it become cooler." Then he again wanted to pronounce the Adhan but the Prophet; said to him, "Let it become cooler." The Mu'adh-dhin again wanted to pronounce the Adhan for the prayer but the Prophet ﷺ said, "Let it become cooler," till the shadows of the hillocks become equal to their sizes. The Prophet ﷺ added, "The severity of the heat is from the raging of Hell."  

كُنَّا مَعَ النَّبِيِّ ﷺ فِي سَفَرٍ فَأَرَادَ الْمُؤَذِّنُ أَنْ يُؤَذِّنَ فَقَالَ لَهُ أَبْرِدْ ثُمَّ أَرَادَ أَنْ يُؤَذِّنَ فَقَالَ لَهُ أَبْرِدْ ثُمَّ أَرَادَ أَنْ يُؤَذِّنَ فَقَالَ لَهُ أَبْرِدْ حَتَّى سَاوَى الظِّلُّ التُّلُولَ فَقَالَ النَّبِيُّ ﷺ {إِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ}  

While the Prophet ﷺ was on a journey, he said (regarding the performance of the Zuhr prayer), "Wait till it (i.e. the weather) gets cooler." He said the same again till the shade of the hillocks extended. Then he said, "Delay the (Zuhr) Prayer till it gets cooler, for the severity of heat is from the increase in heat of Hell (fire).  

سَمِعْتُ أَبَا ذَرٍّ ؓ يَقُولُ كَانَ النَّبِيُّ ﷺ فِي سَفَرٍ فَقَالَ أَبْرِدْ ثُمَّ قَالَ أَبْرِدْ حَتَّى فَاءَ الْفَىْءُ يَعْنِي لِلتُّلُولِ ثُمَّ قَالَ أَبْرِدُوا بِالصَّلاَةِ فَإِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ  

The Mu'adhdbin (the announcer of the hour of prayer) of the Messenger of Allah ﷺ called for the noon prayer. Upon this the Messenger of Allah ﷺ said: Let it cool down, let it cool down, or he said: Wait, wait for the intensity of heat is from the exhalation of Hell. When the heat is intense, delay the prayer till it becomes cooler. Abu Dharr said: (We waited) till we saw the shadow of the mounds.  

أَذَّنَ مُؤَذِّنُ رَسُولِ اللَّهِ ﷺ بِالظُّهْرِ فَقَالَ النَّبِيُّ ﷺ أَبْرِدْ أَبْرِدْ أَوْ قَالَ انْتَظِرِ انْتَظِرْ وَقَالَ إِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ فَإِذَا اشْتَدَّ الْحَرُّ فَأَبْرِدُوا عَنِ الصَّلاَةِ قَالَ أَبُو ذَرٍّ حَتَّى رَأَيْنَا فَىْءَ التُّلُولِ  

The Mu'adh-dhin (call-maker) of the Prophet ﷺ pronounced the Adhan (call) for the Zuhr prayer but the Prophet said, "Let it be cooler, let it be cooler." Or said, 'Wait, wait, because the severity of heat is from the raging of the Hell-fire. In severe hot weather, pray when it becomes (a bit) cooler and the shadows of hillocks appear." (Using translation from Bukhārī 535)  

أَذَّنَ مُؤَذِّنُ رَسُولِ اللهِ ﷺ بِالظُّهْرِ فَقَالَ النَّبِيُّ ﷺ أَبْرِدْ أَبْرِدْ أَوْقَالَ انْتَظِرْ انْتَظِرْ وَقَالَ إِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ فَإِذَا اشْتَدَّ الْحَرُّ فَأَبْرِدُوا عَنِ الصَّلَاةِ قَالَ أَبُو ذَرٍّ حَتَّى رَأَيْنَا فَيْءَ التُّلُولِ  

[Machine] "We came from a funeral, and we passed by Abu Dharr. He said, 'We were with the Prophet ﷺ on a journey when the Muadhin (caller to prayer) wanted to call the Adhan for Dhuhr prayer. The Prophet ﷺ said, 'Cool down (wait), then he wanted to call the Adhan again, and the Prophet ﷺ said, 'Cool down,' and on the third time he said, 'The third time is the most knowledgeable. Then we saw the shade of a tree and the Prophet ﷺ said, 'Indeed, the intensity of the heat is from the heat of Hellfire, so when the heat intensifies, cool down with prayer.'"  

جِئْنَا مِنْ جَنَازَةٍ فَمَرَرْنَا بِأَبِي ذَرٍّ فَقَالَ كُنَّا مَعَ رَسُولِ اللهِ ﷺ فِي سَفَرٍ فَأَرَادَ الْمُؤَذِّنُ أَنْ يُؤَذِّنَ لِلظُّهْرِ فَقَالَ رَسُولُ اللهِ ﷺ أَبْرِدْ ثُمَّ أَرَادَ أَنْ يُؤَذِّنَ فَقَالَ لَهُ أَبْرِدْ وَالثَّالِثَةَ أَكْبَرُ عِلْمِي شُعْبَةُ قَالَ لَهُ حَتَّى رَأَيْنَا فَيْءَ التُّلُولِ قَالَ إِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ فَإِذَا اشْتَدَّ الْحَرُّ فَأَبْرِدُوا بِالصَّلَاةِ  

[Machine] Abu Dharr heard the Messenger of Allah ﷺ saying: "We were with the Messenger of Allah ﷺ during a journey and the Muadhin intended to call the Adhan for Dhur prayer. The Prophet ﷺ told him, 'Cool down.' Then he intended to call the Adhan again and the Prophet ﷺ told him, 'Cool down' two or three times until we saw the shadow of a hillock. The Prophet ﷺ then said, 'Indeed, the intense heat is a portion of the Hellfire. So when it is extremely hot, cool yourselves with prayer.'"  

سَمِعَ أَبَا ذَرٍّ يَقُولُ كُنَّا مَعَ رَسُولِ اللَّهِ ﷺ فِي سَفَرٍ فَأَرَادَ الْمُؤَذِّنُ أَنْ يُؤَذِّنَ بِالظُّهْرِ فَقَالَ لَهُ النَّبِيُّ ﷺ «أَبْرِدْ» ثُمَّ أَرَادَ أَنْ يُؤَذِّنَ فَقَالَ لَهُ «أَبْرِدْ» مَرَّتَيْنِ أَوْ ثَلَاثًا حَتَّى رَأَيْنَا فَيْءَ التُّلُولِ وَقَالَ «إِنَّ شِدَّةَ الْحَرِّ مِنْ فَيْحِ جَهَنَّمَ فَإِذَا اشْتَدَّ الْحَرُّ فَأَبْرِدُوا بِالصَّلَاةِ»  

" كُنَّا مَعَ رَسُولِ الله ﷺ فيِ مَسِيرٍ فَأَرَادَ بِلَالٌ أَنْ يُؤَذِّنَ، فَقَالَ رَسُولُ الله ﷺ أَبْرِدْ، ثُمَّ أَرَادَ أَنْ يُؤَذِّنَ، فَقَالَ لَهُ: أَبْرِدْ، حَتَّي رَأَيْنَا فيِ الْبَلُولِ، ثُمَّ أَذَّنَ فَصَلَّي الظُّهْرَ، ثُمَّ قَالَ: إِن شِدَّةَ الْحَرِّ مِنْ فَيحِ جَهَنَّمَ، فَإِذَا اشْتَدَّ الْحَرُّ فأبردوا بِالصَّلَاةِ".