Now we're getting into dangerous territory.
Purests will say neat (without mixer, water or ice). "Sippin'" Whiskey originally (so I've been told) referred to aged/smooth whiskey as opposed to what comes out of the still (back when many people, including George Washington, made their own).
However, back in the 70's I visited the Black & White Distillery outside of Glasgow and they added a spash of water to their whisky prior to serving it. Also, in the 90's when passing through Heathrow I stopped for a taste at the Duty Free and the young lady advised I should try the Single-Malt (I forget which brand) with a little water to "open it up."
Fine Liquores and Brandy should be enjoyed undiluted at room temperature, or slightly warmed either by hand or a gentle flame (outside the glass!) so that one may savour the aroma.
Im going out on a limb here saying fireball whisky isn't a "fine liquor", but it's marketed as freezer whisky. Canada sells beer /coolers in walk in coolers. The USA has little fridges for whisky/hard liquor in some stores. It threw me when getting asked "hot or cold"
But then again the drive thru liquor stores are unique to the USA too
I horrify people drinking room temperature beer.

There's also the tomato juice versus Clamato juice argument too