I used to pray Zuhr with the Messenger of Allah ﷺ, and I would take a handful of pebbles to let them cool in my palm so I could place them where my forehead would rest and prostrate upon them, because of the intense heat.
كنت أصلي الظهر مع رسول الله ﷺ فأخذ قبضة من الحصى لتبرد في كفي أضعها لجبهتي أسجد عليها لشدة الحر.
Abu Dawud (399) and Nasai (1081) both narrated it through Abbad bin Abbad, who said, Muhammad bin Amr narrated to us, from Saeed bin Harith al-Ansari, from Jabir bin Abdullah, and he related the hadith. The wording given here is that of Abu Dawud.The wording of Nasai is, "I would take a handful of pebbles in my palm to let them cool, then shift them to my other palm, and when I prostrated I would set them down for my forehead."Its chain of transmission is hasan, for Abbad bin Abbad, that is Ibn Habib Azdi, and Muhammad bin Amr bin Alqama, are both trustworthy narrators.Among the legal points it contains is that a minor action does not invalidate the prayer.