A person hears their name called out across a crowd, and instead of feeling comforted, they feel wounded. The caller's eyes are "dark with concern," so he seems to mean well, yet the sound of his voice lands like "a shard of ice." The poem never says why the speaker reacts this way, and that gap is part of what makes it unsettling.
The speaker's feelings come through in the body rather than in direct statements. Skin is "raw," blood "poured" and "dotted the ground," and the final image is of shivering. Judging by this imagery, the speaker may be already vulnerable or exposed, so even kindness feels sharp. Being noticed in a crowd, when you would rather stay hidden, can feel like that.
The mood is cold, tense and quietly painful. The short lines and lack of punctuation make the moment feel suspended, as if the speaker is frozen in place while everything happens around them. The title, "Frostbite," fits: it suggests numbness and damage caused by exposure.