I just filled up a milk jug and an old plastic coffee container with ice & a little water and set it in the water bowls.
Supposed to be 101 today here in Mesa AZ so I also ran the sprinklers before I went to work to get the ground wet around the run areas (not really IN the runs, just barely sprinkled the edges) and I put a wet towel over an area of the run for evaporative cooling and additional shade. Hoping that will help keep them cool until I get home after work.
first thing I thought of was icw as well .. i will do that for the dogs in hot summers.. i know its harder with the nipple waterers.. so maybe a combo of ice and wrapping with insulation would do the trick.. I know Im going to be dealing with the same problem this summer too.. I was also thinking of setting up a mister over the coops run.. like the ones they have at Zoos etc. that are in the vine archways that you walk thru that have the misters in there and you cool off as you walk thru.. I know they have them for dog kennels so im sure I can rig it to work on the chicken coop runs..
good luck with the heat.. )O(