Do these really keep you cool(ish) in the heat?
I ordered some Coolibar clothes for YDS today, after his eczema responded poorly to the sunscreen I put on him yesterday (Supergoop that I loved, but his skin didn't). He's on regular antibiotics, while undergoing chemotherapy, so he needs something extra to protect him from the sun. But, he's 3, so keeping him out of the sun doesn't work very well.
My skin is sun sensitive both naturally as well as due to medication. I burn extremely easily and get rashes from sun exposure. I also get adverse reactions to almost all sunscreen/sunblock. I cannot use any of the chemical sunscreens, and most brands of mineral sunblocks will also cause a reaction.
I can use Vanicream and Blue Lizard brand mineral sunblocks (at least one also has versions that have sunscreens, which I can't use).
But mostly, I use sun protective clothing, including a wide brimmed hat, with UPF 50+. The clothing covers almost all my exposed skin and minimized the need for any sunblock. With the right fabrics and clothing design, I am actually cooler and more comfortable fully covered than in shorts and a tshirt. For swimming I wear a long sleeve UPF rashguard and swim tights.
There are a number of brands that sell quality UPF 50+ clothing. I prefer going with well known brand names instead of knock-offs where I don't know what I am actually getting. Coolibar, Solbari, LLBean, and Lands End have excellent UPF clothing and swimwear. Eddie Bauer, Outdoor Research, Ex-Officio, Columbia, also offer some options. Coolibar is my favourite for UPF clothing and that is what they specialize in. One thing to pay attention to is whether the UPF protection is there for the lifetime of the fabric or will it wash out -- there are treatments that can be added to fabric, but they are temporary versus the inherent design of the fabric itself.
Something I will often do is wear e.g. a normal shirt and then have a UPF coverup or jacket over it. Allows me to resuse the coverup/jacket from day to day, as well as take it off indoors if I want, but still get the sun protection. Also less expensive than have an entire wardrobe of UPF tops.