It is narrated from a Companion (may Allah be pleased with him) that the Noble Prophet (peace and blessings be upon him) said: The intensity of heat is due to the effect of the heat of Hell, therefore when the heat is severe, perform the prayer after it has cooled down.
Hadith Referenceمسند احمد / مسند الأنصار رضي الله عنهم / 23119
Hadith Gradingحکم دارالسلام:صحيح لغيره، وهذا إسناد ضعيف لجهالة حجاج