Looks cool! Pun intended.
During an Alps tour, I was the only rider in the group that had a water-soaked cooling vest as we entered Italian valleys that hit 100F. I feared for my safety from the other sweltering riders!
The vest lasted about an hour between soakings (covered by a open-mesh Motoport kevlar coat). It didn't require electrical power.
I found that if I could keep my torso cool, my head was happy to go along for the ride.