After that lovely chat with the first ("woman? man? alien who does not follow your puny human gender construct?" is what would be put here if this isn't an AU) person he runs into, his lungs start lodging their complaints by punching him with random expels of air. By the third person he's chatted with, it's turned into a cough here and there. Now he's leaning back against a light pole, hunched over and not quite gasping for breath yet, but still visibly struggling for air.]