I wear my blouse at the regionals every day. Have always done it. Will always do it. My aircraft frequently gets well over 100* in the cockpit. The best I have seen was about 125. Haha. The way I see it, if you look like a truck driver. You will be treated like one. So I wear the coat walking to and from and while addressing my pax or doing a walk around. It's really not that big of a deal. And you look sharp. But then again I cut my hair, shave, and shine my shoes also.

But a lot of this is for passenger perception. If they see you looking sloppy it comes off bad. You all don't have to worry about that soo much.