On my travels last summeer, i fell in love with the Gander Mountain Guide Series convertible pants. But, it occurred to me on my adventures that I was still wearing the same old t-shirts I'd always worn, and those weren't ideal for hiking conditions. Wet Cotton is not very friendly in adverse conditions save for perhaps the desert where you can count on evaporation cooling. I distinctly remembering being absolutely miserable in my shirts some years on car camping trips. Normally I love high temperatures and high humidity, but the real key things there are (1) I like not doing anything in those conditions, and (2) I wear as little as possible. Not really the sort of conditions you'll encounter on the trail.
So, before Bob and I went off to Flint Ridge near the Klamath, I stopped at a local outfitter. Browsing their shirts, I found some rather nice ventilated shirts from The North Face. I'd been hoping for something that zipped open at the elbow, the shirt equivalent of my convertible pants. No dice. But close enough, I found these north face shirts had a button to pin a rolled up sleeve Just below the shoulders, but above the chest pocket, they have hidden vents beneath a fold, that lets the shirt breathe. Much like the nylon pants, these shirts are very lightweight. a bit pricy though, I'm astounded how much some of this clothing can cost. Lucky for me, I found one left, in just the right size in a tan/khaki color at Scheels on clearance for like 40% of the cost I paid for the first. Score.
Pretty much everything I listed as an advantage of the convertible pants holds true for these cool breeze shirts. They're lighter weight and quite well suited to many of the conditions you might encounter on a backpacking trip. You'll probably want, as with the pants, to have a base layer option because while they block the wind, layers are important when you want to stay warm. I don't often get this excited about a shirt with buttons... actually, I don't often get this excited about any sort of clothing, but I'm quite fond of these shirts. Definitely recommended.