Frost starts as a physical sensation: the speaker breathes in freezing air and feels it spread through the body like a cobweb of ice. The speaker becomes "the pitiful prey," caught and held by nature. The shivering, chattering teeth and stinging skin build a sense of helplessness, and the "frostbitten heart" suggests the cold is also emotional, a numbness that seeps in until feeling stops.
The final lines shift from the body to love. The speaker says acceptance can't be forced, that love follows its own course, and that everyone has the right to refuse another. Judging by this turn, the cold may stand for rejection, either being turned down or having to turn someone else away. The tone is quiet, bleak, and resigned. Instead of anger, there is a painful acknowledgment that nobody owes anyone love, even when its absence hurts like freezing.