Stiles knew Lydia far too well to believe her, especially given that she didn't even look up at him. Seeing her just laying there, doing nothing, was so out of character, that he was instantly worried and wondered if he needed to reach out to one of the doctors around camp to come and take a look at her.
Not wanting to jump the gun, he decided to lie down next to her. "Try again," he said. "What can I do?"
He might be feeling a bit more attentive at the moment because of Isaac and Derek's comments implying that he wasn't capable of being the support system that Lydia was going to need over the next few months.