I am, uh, well insulated, so my body operates at higher temperatures than most people. I often need some air circulating through my clothes to cool me. Maybe he is a walking furnace like I am, and he is unawares that his behavior is distracting. I'd mention it to him.

(I've told my T TWICE to watch out what she wears with jeans because I have seen more than I have ever wanted to see of my T! And I did use the words "trauma" and "disturbing.")