Call me weird but I never drink whiskey cold. If adding water, it is just from the tap and never ice water. Adding an ice cube turn me off big time. Whiskey should be enjoyed at room temperature. When you chill down a liquor, that kills the flavor and it basically means you don't like the taste of what you are drinking.
I even feel the same way with vodka. I drink shots of it at room temperature, with pickles and rye bread or other such savories, as people do in Poland and Russia. Here in America, we get watered down tutti fruity vodka and only make mixed drinks and ice the hell out of them.
In those old countries, they still mainly drink vodka as was traditional, at room temperature (sometimes cold in restaurants and bars nowadays) in one shot and it has no sugar no tutti fruity juice just VODKA: i.e. ethanol and water! Best way for sure, the salty snacks are great with it and can kill any harshness.
But back to whiskey, yeah, no ice or cold water in the either.
But as for HOT, well I have been making hot buttered rums as a nightcap for the past few nights, getting it down pat. Might have to make a hot buttered rum thread!!