This fella's undercoat was a little frosty, but as I am told, that's common in the summertime (especially here in the Deep South). 

Prēost — The equivalents of Chaplains within the ranks of the Greymanes. Their head is the Heah-Prēost, whose office combines the duties of the Chief Apothecary, Reclusiarch, and Master of Sanctity. Whilst the Chaplaincy and Apothecary are effectively one organization, the remits of a singular Prēost are either spiritual or medical, and never combined. Their roles are denoted by the color of their armor, and by their titles. The Laece-Prēosta (meaning "leech priests", a testament to New Albian medicine's primitive state) wear white, while Prēosta proper wear black.

This fella is a Prēost proper, hence the black armor and general Chaplain-y accoutrements.