"We used to pray Zuhr with the Messenger of Allah ﷺ and I would take a handful of pebbles in my hand to cool them down, then I would pass them from one hand to the other, and when I prostrated I would put them down to lay my forehead on them." (Using translation from Nasāʾī 1081)  

«كُنَّا نُصَلِّي مَعَ رَسُولِ اللهِ ﷺ الظُّهْرَ فَآخُذُ قَبْضَةً مِنْ حَصًى فِي كَفِّي أُبَرِّدُهُ ثُمَّ أُحَوِّلُهُ فِي كَفِّي الْآخَرَ فَإِذَا سَجَدْتُ وَضَعْتُهُ لِجَبْهَتِي»