She doesn't notice him at first, which says something about the state of things because years of training has taught Katniss to be vigilant above all else. But she doesn't notice - or doesn't care, either way she doesn't respond to his words and doesn't bother to wipe her eyes. She lets the curtain of untied hair hide them for her, but it's obvious that she's not going to be able to pass this off as anything else.

Her shoulders are shaking enough to let him know that she's alive, at least. And why is it that he's always around at the worst times? When she's tried so hard to build up a good wall between herself and everyone else on the island. And now he was going to see her like this. The snow leaches some of the excess heat from her body and her face, and she burrows it deeper into the mound, grateful for the relief.