He notices, but only just. Fortunately for Jyn, he merely thinks she is cold, because she is always cold. Too bad he doesn't have a coat to offer her. Maybe he should have brought one for that express purpose! Good job not thinking ahead for once.

"The sun here is bright! Sunglasses are clearly more important than a jacket." His hands move lower as the buttons do, practically courting the bottom of her spine. He closes them up slowly, though not on purpose - it's almost like he's extra afraid of a slip up down here, where he is trying to pretend he can't see the waistband of her underwear peeking out.

No slip ups. Just his heart pounding which he is sure she can hear. "You can borrow them, but I will need them when the sun is actually out again."

The sun hurts his eyes!