what about using a chinchiller, you can even put it in the frig to cool it off more before going in the cage, you can also cool their dust in the frig then let him take a bath.. or you can put some ice in a bottle but seal the bottle up with fleece [for the condensation] and he can lay next to it to keep cool.. i have never done that one, but i have heard people talk about it before.
as for the ice water, i wonder if that woudl be okay.. i mean think about if you drank really cold water when you were really hot, doesn't it bother your stomach, it does me, but maybe i'm just weird... lol.. but anyways, what if that happened to them