Boiling point of caffeine is 178C (sublimates), compare cocaine at 187C, looks like it would work as long as theres no mineral acid in it (shouldn't be!). You got me curious to try it, bet it tastes like shit! I really don't like espresso.

You could bake coffee in your car in the morning without danger of spillage! I'd rather show up for work with a tiny burn hole in my pants than a foot-long brown stain.