“You’re one of the least selfish people I’ve ever met, Sam,” he huffs a soft sigh.

That hand on his cheek gets a little shiver, the difference of temperature between Sam’s fingers and Bucky’s face is… stark. It isn’t fair, he’s still so much warmer than he should be by now because of the serum, but not warm enough to stave off the cold for Sam.

“Hey…” he nudges him, gentle but firm. “There’s nothing to forgive,” he assures him.

Light-headed? Not good. Bucky can feel the panic rising like bile in the back of his throat. “don’t you go to sleep on me.”