Well, it is a shirt. I don't know what a chiton is, admittedly.

[Facts!! If he had to guess based purely on, hm, remaining clothes, he might guess a jumpsuit of some kind? Who can say. He's not guessing, but instead plucking at his slowly drying shirt, which of course does nothing to prove its worth as armor.]

As for bare skin, there's contact dermatitis, for a start. The rather large fire just over there is spitting out all kinds of smoke that just might make me break out in hives, you know. Don't get me wrong— there's merit in the knowing, but I'm not really in the mood.