A kidney stone is condensed, something like hard, frozen energy. In order to offset that, we need to apply something with the opposite, activating energy. We should apply heat. Heat will activate this frozen energy and make it melt and break down. A hot ginger compress can be applied for that purpose.
Fever represents the opposite type of energy.
Fever is an example of hot, overactive energy. Something with cool, inert energy. Ice is too cold for this purpose. Ice is so cold that it makes the body contract, so that the excess that is trying to come out through the fever will, instead, be held inside. Something a little milder is needed.