Prepare to be amazed by our range of fantastic heat changing mugs. Simply pour your favourite hot beverage in and watch the design magically change before your eyes. As the contents of the mug cool the design will change back to its original state. Printed in vibrant colours and fully dishwasher safe our hat change mugs are a great talking point and a great gift when you are looking for something that little bit different. This Transport For London mug shows the iconic London Underground tube map in all its glory.