Re: Got a few questions....
I have never understood. I think its more of a sensation from the shisha. I used day-old room temperature water when smoking blue mist, and it felt cool because of the tobacco. I think the mints especially, will feel cool. And I have never noticed the smoke being any thicker as a result of the ice. It comes down to bowl setup and heat management. Nothing more.
Live, learn, love hookah.