Abu Khulda reported that he heard Anas ibn Malik when he was withal-Hakam, the amir of Basra, on a seat. He said, "When the Prophet, mayAllah bless him and grant him peace, was hot, he delayed the prayer untila cooler time of the day. When it was cold, he made the prayer early."
English reference: Book 47, Hadith 1162
Arabic reference: Book 1, Hadith 1162