Where does “ephippium” come from?

ephippium (Latin) comes from Ancient Greek ἐφίππιον, from Ancient Greek ἐπί, from Ancient Greek Ἡμέρα, from Ancient Greek ἦμαρ, from Proto-Hellenic ā́mər, from Proto-Indo-European h₂eh₃mr̥, from Proto-Indo-European h₂eh₃- — to be hot; to burn.

ephippium (Latin): saddlecloth, caparison