The ring of warning, and only that, should indicate the exact amount of turns you have left to live when afflicted by a timed instadeath such as sliming, stoning, or strangulation. (And drowning and other forms of suffocation in variants that have that.) This feedback is conveyed by the ring vibrating that number of times, e.g. “Your [ring] vibrates twice.” Possibly it should only happen when the amount of turns to live is low because it doesn’t make that much sense for it to vibrate 20 times in one turn and have the hero count that accurately.