Having recently spent a bunch of time in some of the world's hottest deserts, I wonder why no one has marketed a portable solar umbrella hooked up to a drinks cooler, or small cooling fan, or one of them electric cooling collar contraptions. Googling for 'solar umbrella' points to large unwieldy umbrellas good for patios and backyards - hardly convenient for hauling around. Making these should be a no-brainer. You'd have to fix flexible solar panels on top of a folding umbrella, and...