The Doctor, having properly thawed out from his adventures outside, was not doing what one might expect and dealing with the snakes. Let his other selves worry about it for the time being. He had more important things to do, like looking after Rose. He knew she was having a hard time of it with a second version of herself on the ship and him getting into tough spots, and he wanted to do something for her. What, he had no idea, so he simply set out to find her so they could spend a little time together.
He eventually found her in the sun room, curled up in one of the chairs, and quickly crossed the room to join her, crouched beside the chair with one hand stretched out to rest lightly on her knee.
"Hello," he said, softly, in that way he had that seemed to also say, "I love you," with that single word.