It is narrated from Hazrat Abu Saeed Khudri (may Allah be pleased with him) that the Prophet (peace and blessings be upon him) said: (When the heat becomes intense) perform the Zuhr prayer at a cooler time, for the severity of heat is from the effect of the heat of Hell.
Hadith Referenceمسند احمد / مسند المكثرين من الصحابة / 11497
Hadith Gradingحکم دارالسلام:إسناده صحيح، خ: 538، وانظر ما قبله