Ianto hummed appreciatively under his breath, both at the idea of Sulu bringing some of his coffee with him onto the Enterprise, and also at the feeling of Sulu's fingers in his hair. Sulu should have known better than to start petting his hair, though, if he wanted Ianto to stay awake at all. Sure enough, not very long after Sulu had started the continuous, soothing motion of running his fingers through Ianto's hair, Ianto shifted his head to the side in a last minute attempt to keep his head from lolling at quite so awkward an angle, slowly letting himself fall asleep.

It wasn't just that Ianto was falling asleep, though. He'd slept a bunch of times before that day. But there in the bath, Ianto was finally warm after being so very cold for so long. He knew that he was safe, that for the time being Sulu would keep him safe and warm and keep his head above the water for that matter, and that was all he needed to absolutely conk out. He would have felt a little guilty about it, but there was such an overwhelming feeling of relief that washed over him that he couldn't really bring himself to care all that much before he was out completely.