Chewing ice isnt bad for your liver or intestines or stomache. These are all myths. Think about it, do popsicles hurt you? No.... Ice is water by the time it reaches your stomach anyway (unless you are swallowing the ice whole)
ice = water. cold water. it wont hurt you, it wont put you into shock or cool your core temperature down, or give you hypothermia... it wont cause you to die, or even get hurt, it might give you "brain freeze" but other than that its fairly harmless.
Oh, and by the way, ice chewing is VERY annoying to those around you, please be considerate. You wouldnt smoke around a non smoker if they asked you not to, so why chew ice??