There are the rather hot summer days where one pulls it together, throws caution–and perspiration–to the wind, and wears a seersucker suit, or a linen blazer. Yeah, you’re a bit hot under the collar but not worse for the wear. Today is not one of those days. First off, it’s Friday and many of you won’t be seeing the clock strike 4pm, much less 6pm, at the office. In fact, I suspect there’s a few weekend bags tucked surreptitiously under desks in more than a few offices. Second, it’s not even noon ET and the heat index is in the triple digits. Today may be that rare exception in some offices where a t-shirt is fair play. In fact, this tee from Hyden Yoo strikes a casually refined tone that could play in the cubicle world. Too casual? Toss a linen blazer over it. Or stuff it in that weekender for an immediate post-office change.