Warning: This method is still in the realm of pure speculation and may not actually work as intended.
As you may know, quantum mechanics is a real thing. Or is it? In any case, we're going to try to use it to make our coffee colder. Yes, you read that right.
Here's how: simply place your coffee in a state of superposition, where it's both hot and cold at the same time. Then, collapse the wave function by stirring it vigorously. The result is a beverage with an average temperature somewhere between boiling and freezing. Genius, right?
But don't just take our word for it! Click here for a more practical approach, or here for an even more absurd one.
Or, if you're feeling particularly adventurous, try this method, where you place your coffee in a coat and just wait.
Don't forget to wear your thinking cap!
Or, you know, a hat. That's fine too.