Aisha bint Abi Bakr · The Book of the Prayer

The Prophet used to pray Zuhr when the sun had passed its zenith.

We were praying Zuhr with the Messenger of Allah at the time of intense heat (i.e., midday when the sun has just passed its zenith) and he said to us, "Wait for it to cool down before you pray, for intense heat is from the flaring up of the Hell-fire."

The Messeenger of Allah said: "Whoever catches one Rak'ah of the Subh before the sun rises, then he has caught it, and whoever catches one Rak'ah of the 'Asr before the sun sets, then he has caught it." (Sahih)Another chain with similar wording.