It wasn't in his nature to care, Kristoff thought to himself. He had taken her to the North Mountain, and he'd helped get her back to Arendelle, but it was because he needed the money. It wasn't anything else.
And of course he'd carried her when they had arrived at the castle, she was too weak at that point to walk, and of course he was grateful when the spell broke and Anna was better, who wouldn't be? It was pure luck that Hans had just gotten back with Elsa, because imagine if they hadn't gotten to Elsa right away...