York put his hand on Wash's thigh when he saw his friend rub his forehead. Maybe talking about it wasn't the right thing to do if it caused him pain. "I can't imagine what it's like for you, Wash," he said softly. He could hardly wrap his head around what had happened to his friend, let alone the long term effects of that.
"I can't help the things going on in your head, but if you'll let me, I'd like to at least try to keep the nightmares at bay. If only for a couple of hours." York wasn't sure if it would help, if it would make a difference, but he hoped. And that hope was enough to get him to offer even if it might just confuse Wash more. Even if it didn't help. They needed to do something or else Wash would end up falling asleep somewhere he shouldn't and someone could really get hurt. They'd been lucky, in a sense, that it had been Charlie.