Burning Cup by Ryan Jongwoo Choi is a stylish looking mug with a twist. Between the inside and outside of the mug, there’s a sheath of sodium acetate. When the drinker presses on one of the rubberised buttons on the side, the disturbance cause the sodium acetate to solidify and release heat, thus heating your coffee and trapping the heat inside and maintaining the temperature of the coffee for longer. As the coffee inevitably loses heat again, it is transferred back to the sodium acetate which turns it back into a liquid and effectively resets the whole process.
And if you’re still not impressed you must be trying pretty hard, so how about this… there’s also a thermochromic plastic ring around the bottom that changes from red to blue, allowing you to see the temperature of the cup.