Sunan Abu Dawud
660
Sahih+3

Anas b. Malik said:we used to pray along with the Messenger of Allah (ﷺ) in intense heat. When any of us could not rest his face on bare ground while prostrating due to intense heat he spread his cloth and would prostrate on it

SahihAl-Albani
SahihMuhammad Muhyi Al-Din Abdul Hamid