Fiqh-us-Sunnah Volume 2, Supererogatory Prayer, Fiqh 2.086C.
Section : Prostrating upon one’s clothing or headdress due to some excuse.
Ibn ‘Abbas reports that the Messenger of Allah prayed in one garment and covered his face with a portion of it to avoid the heat or coldness of the ground. This is related by Ahmad with a sahih isnad (chain). It is disliked if it is done without any genuine reason.