I have a few pair of something similar to those, mine are zip offs. I've had them for years and use them specifically as a windblocker. I should probably buy a pair of those you linked to. Mine are way past out of style and none of the stores sell them anymore.

One of those SOL emergency blankets will keep you warm in the conditions you describe if you have some good insulation under it. I've carried those E-blankets for years, but only really started using them the last couple years after I decided I wanted to test one. Used with even a cheap layer of fleece they are amazing.

I should probably be testing one now to see how well they work to provide some shade. It's been "Sunny and Hot" here for over a month straight now