Study the properties of the stone.
Some stones emit energy others absorb.
Each stone has the properties of different plants and elements.
I don't think there is a problem if they are good pairs of stones.
I've read the recommendations many times. a h
I think your organism takes advantage of it if you do it intentionally.
I mean that you don't get the shock of the cold bite but rather you feel it as fresh water on your body.
I have taken cold showers, but not regularly as I probably might...