When the heat is intense, delay the prayer until it becomes fairly cool, for intense heat is from the boiling and breathing of Hellfire

Explanation

The Prophet (may Allah's peace and blessings be upon him) ordered that the Zhuhr Prayer should be delayed when the heat is intense, which is from the breathing and blaze of Hellfire, to a time when it is fairly cool, so that one is not distracted by heat and grief from submissiveness in prayer.