Here in the desert, it doesn't matter what "cool" surface you place on the pool deck, it's going to get uncomfortably hot to walk on. A quick dousing of the deck with a couple of buckets of water cool it down nicely.
Since I was going to re-do my deck with travertine, I was thinking I should install a couple of rotor sprinklers that would spray down the deck & pool for a couple of minutes to cool it off. The water source would come from the current pool fill line, that's actually after my water softener. Can anyone think of a reason not to do this, other than it makes the entire deck slippery all at once?