I didn't even know these were a thing until recently.  It sounds like a great idea but I'm really dubious of the claims that they cool you instead of making you warmer.  

I can see if you're wearing one as your shirt but I was thinking more of something I can throw on over a t-shirt if I'm going to be out in the sun enough to get sunburned.  I'm so white that I burn really easily.  Plus it would make a good cover garment for concealed carry on hot summer days.  

It seems like a great idea but with the heat and humidity here I wonder if it will just make you hotter when wearing over another shirt?  They're designed to keep you cool but that might only work if it's the only layer you're wearing.  

Anyone tried these?  They seem to be super popular with fishermen and people who are in the sun a lot.

When I'm cutting grass in the middle of the summer, I wet an old t-shirt.  Poke the top of my head through the neck opening and wear it like a headband.  Let the body of the shirt flop over my back.  The sleeves over my ears.  Put on headphones for tunes.  And mow.

Noticeable evaporative cooling effect.  

I haven't done the hoodie, but I have begun using protective sleeves made out of that same material during the summer, and it does make a big difference in a good way.

I've worn one when fishing and hiking.

Did you wear it as your shirt or over a shirt and how did it work?

Yeah, I was thinking of it as something to keep the sun from burning me not so much the cooling part for that reason.  I was just wondering if they increase your heat in that situation.

That's what I was thinking.  It's not exactly a good trade off to protect you from the sun but make you even hotter in the process.

Plus you look cooler which is always a plus.

I haven't seen these.  My idea was kind of like a raincoat except for the sun. Put it on over your normal clothes when out in the bright sun and take it off when you're out of the sun.  It doesn't seem to exist though as everything I've seen are basically hooded shirts and designed to be worn as a shirt.  Too dang expensive to use them that way in my opinion.

They are awesome, bought a bunch for family and friends after I saw an instructor wearing one during a shooting class. I always cover up on the range or outside for extended periods in heavy sun. Big ridiculously hat, neck wrap, long shirts. I look very Arabian. These can cut down on the garb. They even make ‘‘em with a face shield in the hood, I think that is for sun wind protection not a vivid think. These have cut the garb down a bit. I don’t think they make you cooler other than all these are “dryfit” nylon so they won’t get soaked with sweat they just protect from the burn in a better way. Different manufacturers have different sun protection ratings based on construction and materials. I got a bunch from Epic Sports $ 10-15. for a basic hooded long sleeve drift shirt. Walmart Bass Pro carry them in stock pricer I’m sure.

I’ve seen them…worn by the Ginger class and fisher men/women.

Most of the high SPF fabrics are such a tight weave they trap some body heat as a result. I have some by Columbia that make me hotter but one that has a texture to it is more comfortable. Simms solarflex fabrics are the best I have used, they actually breathe and feel cool on the skin while still providing protection from the sun. They snag easily though, all of mine have little pilled spots where I caught them on something.

Good info, thanks!