So crisp and refined. A short thought, but anything more and it would ruin this poem's effect. To start it with "Because" seems very fitting because... well, I keep thinking of transformations or metamorphoses, and the title automatically made me think along those lines. So it's as if you began the poem in the middle of one of these transformations... someone fading slowly like the remaining embers of a fire. That's really a tragically beautiful way to express loss, be it physical or spiritual.
Ash begins to ice is very resonant in and of itself. Good work.
Short and powerful, lovely but sad images, feeling the heat and the chill... I think of Frost's "Fire and Ice." It sounds like a death, either literally or not, the death of something that remains caught, because nothing can melt in the cold. These opposites are well described and combined in this poem.