Final answer:
The phrase implies a sense of inevitable discomfort and hints at an advancing sickness or emotional coldness, complementing the themes of struggle and isolation in the text.
Step-by-step explanation:
The phrase "I could feel the cold settling in" conveys a sense of discomfort and the encroachment of a relentless, possibly harmful influence. It suggests an unavoidable onset of illness, where the cold is both a literal drop in temperature and a metaphor for the unforgiving advance of sickness. The underlying imagery used throughout these lines helps to illustrate the theme of struggle against a faceless and overpowering adversary, be it cold, disease, or emotional isolation.