It's easy to shop around Macy's this time of year, lightweight button downs primarily in cotton work best during summer.
Polyester: Breathability vs. Wicking? - Page 2
I put on a poly wicking shirt the other day, and immediately felt suffocated and started sweating immediately.
So, yes, it wicks away the sweat, but if I was wearing cotton, I wouldn't be sweating in the first place!
This article talks about how poly wicking shirts reduce breatheability and leave moisture on your body.
Edited by Reevolving - 7/17/13 at 9:34am
No one has explained to me how moisture wicking and/or quick drying fabrics keep you cool.
Being wet keeps you cooler than being dry. You loose the cooling property of sweat if the fabric pulls the moisture from your skin by mechanical action, rather than your body heat converting the liquid sweat into water vapor and absorbing a ton of heat energy in the process. Has towel-drying after a shower ever cooled you down? No, but air drying sure has.
If the quick drying fabric dries because your body heat is used to evaporate it off the fabric, well maybe that helps cool the shirt and you a little I suppose. But it would seem to me that there is a good amount of sweat that evaporates off of part of the shirt or pants that is not in direct contact with your skin--i.e., it is not pulling actual body heat but radiated heat that already left the body and/or the heat of the sun or surrounding environment.
In fact, if I was stuck in a hot desert environment with a cotton rag and a lake, I think I might just soak the rag and put it on my neck or head because the cotton would keep wet and cool for longer.
With all that being said, poly wicking fabrics are good for sports for a couple of reasons:
if you are playing basketball or running or doing something high intensity where you are dripping with sweat and moving, then cotton sticks and rubs to your skin and creates raw spots and blisters and sucks;
if you are hiking in the wilderness with cool nights or rain or the threat of hypothermia--then you don't want to be in sweaty wet cotton clothing as it will chill you to the bone. I guess in other words, wicking/quick dry is good to keep you warmer than you would otherwise be, not cooler. I fail to see how it could do opposite things at the same time (which many manufacturers claim).
That said, when you are traveling in a very hot environment and want to pack for it, poly blend travel shirts have the advantage of not showing wet sweat marks. And while cotton and linen are generally more breathable and lighter then many poly fabrics, they do make pretty light, mesh-y poly athletic and golf shirts that breath well too and don't get sweaty. You just have to pay attention to the denier and weave of the fabric (and even low UPF ratings) to determine whether it will wear as cool as cotton or linen. That said I think a loose weave linen makes the best travel shirt and pants overall.
Finally, when it comes to cotton vs. poly boxer briefs, I'm not decided. I feel poly boxer briefs like Ex Officio are less breathable for sure than cotton and it's not like I"m dripping sweat down there (and the fabric does not even make contact with all the nooks and crannies down there to even help wick moisture), but poly stretch boxer briefs are so comfortable on the skin.