Every time I see something like that I am reminded of one of my experiences flying security with The Air Force. One of the Load Masters was wearing his weapon under his flight suit, against his body. He had a standard leather shoulder rig, (AF issue), and nothing between him and the holster.
As we were checking our weapons into a Marine Armory, I watched him pull that little S&W model 15, 2 inch, out of his sweaty flight suit. It was covered with surface rust. Still damp from all the sweat. He tried to hand it to the armor without cleaning it. NO WAY! He cleaned, I watched and the armor got pissed because we were taking his time.
Bottom line, without some kind of moisture protection, I would never put any weapon that close to my body. Especially in any high temp area.
I like the positioning, but I'm with PBSDaddy on the sweaty body. I always wear a tee shirt to help protect me from chaffing with my IWB Alien Gear, but it's a nice thick leather and I don't think much moisture will get on my pistol. It's a Glock, so a lot of it is Poly anyway.
I look forward to the day I can CC a Kimber. It'd be like trading in my Dodge for a Mercedes.