Coolibar has nice long sleeves that are very light weight. I have several, including a bathing suit.

I recently purchased some clothing (swimsuit cover up, hat, long sleeved shirts) that have U.V. protection. I was worried I would be hot wearing them, but I am not at all. They’re made with special material to keep you cool while protecting you from the suns rays.

I use an umbrella whenever I don't feel like wearing long sleeve shirts and basketball shorts(with sunblock of course)