Most coffee bought at stores is cold before they are finished. Dispite the styrofoam cup keepign the temp for a bit longer. An outter foam shell that fits the size cups sold in most stores. Stick in your disposable cup hotor cold for longer life,When finished pull out old cup and dispose properly. Saves finding mold in the travel mugs forgotten in the car and that horrible taste of soap after washing in hot cups of today. Just keep in compartment of your car for use any time traveling.
Reward: whatever one thinks is fair.