The Prophet (ﷺ) said, "Delay the (Zuhr) Prayer till it gets cooler, for the severity of heat is from the increase in the heat of Hell (fire).
Sahih al-Bukhari Book 59, Hadith 69
← Previous Hadith 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).

Sahih al-Bukhari Book 59, Hadith 68 Next Hadith → Allah's Messenger (ﷺ) said, "The (Hell) Fire complained to its Lord saying, 'O my Lord! My different parts eat up each other.' So, He allowed it to take two breaths, one in the winter and the other in summer, and this is the reason for the severe heat and the bitter cold you find (in weather).

Sahih al-Bukhari Book 59, Hadith 70