Sahih al-Bukhari, Hadith 1208 ⓘ
Narrated Anas bin Malik: We used to pray with the Prophet in scorching heat, and if someone of us could not put his face on the earth (because of the heat) then he would spread his clothes and prostrate over them.
حَدَّثَنَا مُسَدَّدٌ، حَدَّثَنَا بِشْرٌ، حَدَّثَنَا غَالِبٌ، عَنْ بَكْرِ بْنِ عَبْدِ اللَّهِ، عَنْ أَنَسِ بْنِ مَالِكٍ ـ رضى الله عنه ـ قَالَ كُنَّا نُصَلِّي مَعَ النَّبِيِّ صلى الله عليه وسلم فِي شِدَّةِ الْحَرِّ، فَإِذَا لَمْ يَسْتَطِعْ أَحَدُنَا أَنْ يُمَكِّنَ وَجْهَهُ مِنَ الأَرْضِ بَسَطَ ثَوْبَهُ فَسَجَدَ عَلَيْهِ.
also referenced under: Book 21, Hadith 12 (In-Book) & Volume 2, Book 22, Hadith 299 (USC-MSA)