With regards to coolers and cold decks it's just not so clearcut.

In normal everyday use cooler and cold-decked is used almost interchangably. In an actual cold deck the deck is stacked intentionally in a way that encourages the players to play a big pot with a pre-determined outcome. In normal usage it refers to the situations where the cards by chance happen to fall in a way that generates a big pot with both parties making the correct decisions.

Unfortunately, Dan Harrington is considered something of an authority on things poker and steps into the breach with a different definition of cooler. Harrington on Cash describes a cooler much as it is described in this thread also - as a card on a subsequent street that 'cools' the action. So where betting might have considered furiously on a blank (maybe in a cold deck situation) and created a big pot the 'cooler' card causes the street to be checked and/or folded rather than bet and/or raised.

While this completes the explanation, I think it will confuse everyone to discuss cooler cards according to the Harrington definition - it's best to just use cooler to describe a situation with something that looks like a cold deck, but which is actually an unintentional cold deck.

I think most famously Daniel Negreanu on HSP season 1 made a call with a full house into Gus Hansen's quads with a shrug and the words: "If I lose this hand it's a cooler."