An officially-licensed Star Wars BB-8 heat change mug by the folks at Thinkgeek:

The BB-8 Ceramic Mug with Lid features one of your favorite astromech droids in a hefty mug, big enough for a Hutt, but made for a human. This mug has a nifty little lid in the shape of the Beebs head to keep your drinks nice and warm. If the beverage is hot, BB-8 will let you know by revealing the control panel, but you’ll have to look closely – he likes to keep it hidden away.

[Star Wars BB-8 Heat Change Mug]