The Prophet ﷺ said, "Intense heat is from the blast of Hell. So when the heat becomes severe, delay the prayer until it cools down."
حدثنا يزيد أخبرنا ابن أبي ذئب عن أبي الوليد وعبد الرحمن بن سعد جميعا
عن النبي ﷺ قال إن شدة الحر من فيح جهنم فإذا اشتد الحر فأبردوا بالصلاة
Its isnad is sahih. Abu Walid is Abdullah bin Harith Ansari Basri, whose reliability was previously established at 2138 and 7126. Abdul-Rahman bin Saad is the Madinan, freedman of Aswad bin Sufyan, a trustworthy tabii, and Ibn Abu Hatim gave his biography at 2/2/237. The hadith has already appeared through two other routes from Abu Hurairah at 7130 and 7245, and it will come again through the route of Ibn Abu Dhib, with this same isnad, at 9094. See also 7246.