Let's be reasonable--your clothing should match your job and your location. If you're pouring asphalt on a hot summer day in Phoenix, wear jeans, boots and a sleevless t-shirt.
If you're a professional however, working in an office is your primary environment. Those offices usually have climate controlled areas, and the time you spend outside is minimal. There's no excuse.
Virtually all outdoor laborers in the desert wear long sleeves...the sweat evaporation theory.
That may be true, but it's tough for me to find a shirt with a large neck and a moderate waistline in the colors/style I like.
As for hot weather, there are tropical-weight wool and linen jackets, but we're not talking about working outside, are we?
I'm a lawyer. I'm inside most of the time but when I have to be in court in a hurray in hot weather, wearing a jacket of any kind is very uncomfortable.
If you're a professional however, working in an office is your primary environment. Those offices usually have climate controlled areas, and the time you spend outside is minimal. There's no excuse.
My (home) office is climate controlled with fans. Fortunately my boss is very practical with his (my) dress code.