He's been using a towel to mop himself off periodically, and he reaches for it now, scrubbing it over his face and then idly tossing it over a shoulder as he rounds the lab extension to stand in front of her, squinting slightly in the sunlight.

"Oh, thanks. Although I probably shouldn't take it now, I'd hate to ruin the dry cleaning job. We could put it inside? I was going to grab some water - did you, uh, want something to drink?"