This is the sort of thing that hosts can (hopefully) head off before by mentioning some things that need to be done "differently" in this household than back home - due to climate, antiques, or whatever.
I grew up in semi-arid West Texas and moved to Phoenix, Arizona (Sonoran Desert) after college. I grew up EXPECTING that any damp towel I dried off with after swimming or showering would dry off quickly, as would my hair (even when shoulder blade length) in an hour or so (at most).
Visiting relatives in more humid areas, a reminder to hang my towel flat so that it could dry or that my hair might still be damp in the morning if I washed it before going to bed was first greeted with skepticism......then dismay when I realized that they weren't kidding (wet braid of hair was still pretty damp the next day - so was my pillow).
Since "the damage is done" the best thing to do is to mention that the chairs in their room are "antiques with the original finish" and that food, drinks, and damp towels need to be left elsewhere, to avoid (further) damage being done to the furniture.
I sleep on antiques when visiting my parents (Great-Grandmother's bedroom suite in one guest room and Grandmother's iron bed in the other) - but the mattresses & bedding are new. Their house has more antiques NOW than it did when we were growing up, as they have inherited pieces. But other families redecorate with NEW furniture, not with OLDER furniture, over the decades - so the guests may not have experience with antiques.