We used to pray the noon prayer with the Messenger of Allah ﷺ, and I would take a handful of pebbles in my palm to let them cool, then transfer them to my other palm. When I prostrated, I would place them down for my forehead.
أخبرنا قتيبة قال حدثنا عباد عن محمد بن عمرو عن سعيد بن الحارث
كنا نصلي مع رسول الله ﷺ الظهر فآخذ قبضة من حصى في كفي أبرده ثم أحوله في كفي الآخر فإذا سجدت وضعته لجبهتي
No references are available.
[Its chain of transmission is hasan] Abu Dawud narrated it, in the Book of Prayer, the chapter on the time of Dhuhr prayer, no. 399, from the hadith of Abbad bin Abbad, through him. It is also found in al-Kubra, no. 668, and Ibn Hibban graded it sahih (Mawarid), no. 267.