Extremely uncomfortable; the mesh type material on the inside top was aggravating to the skin as well as the rest of the shirt. Can't imagine wearing something of this type of material in a hot humid southern climate like south Louisiana. Nothing more comfortable than real cotton!
I originally bought one of these shirts to try it out, but immediately ordered a second. I spend a lot of time in central Mexico where the days are hot and the nights cold. The sun that close to the equator and at 6500ft elevation is much harsher than in the midwestern US, long sleeves are a must for many reasons. In my opinion, his is the perfect shirt for adventure travel, and I am sure its the shirt Indiana Jones would choose if he were operating in this day and age. My only complaint is the shirt is at least one size too large.
I've been fly fishing since the early 80's and over the years have owned just about every brand of 'fishing shirt' on the market. For my money the LL Bean Tropicwear shirt is the best. They're made of the best material, they have the best fit. they have the best size pockets, and they are available in great colors. I have at least 5 of them not counting the ones I've worn out. I wish they still offered this shirt in white; that was my favorite.