Lots of products to stay warm, not so much to stay cool. What about cooling scarves? (cooling socks?)

They seem to come in several forms, including one which relies on water absorbing crystals in order to load more water. I am not sure that I can find them from online retailers, perhaps due to regulations.

Anyone knows anything about these. Run-of-the-mill buffs are ok, but dry quite fast. It may, or may not, make sense to carry a piece of cloth that absorbs enough water to maintain a cooling effect over several hours.