What is the deal with iced coffee? (sorry I've been watching a lot of Seinfeld lately)

You know when you're drinking your coffee in the morning and it sits there a while, then by the time it gets tepid you don't want it anymore because it's too cold. That's funny because iced coffee is always good; however, if the ice melts, your iced coffee is no longer any good. So at what temperature is hot coffee no longer hot? and on the flip side at what temperature does iced coffee become too warm?

That is the puzzle I will be trying to solve today.