question #3 Sahih al-Bukhari 535, Book 9, Hadith 13 : How does the severity of heat relate to the concept of Hell-fire in Islamic belief?

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.”