(10) باب صِفَةِ النَّارِ وَأَنَّهَا مَخْلُوقَةٌ
Narrated Abu Dhar:
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).
Reference: Sahih al-Bukhari 3258
In-book reference: Book 59, Hadith 68
USC-MSA web (English) reference(deprecated numbering scheme): Vol. 4, Book 54, Hadith 480