I like having coffee in a double-skinned, stainless steel cup, which keeps the outside cold and the inside hot.
Some people of my acquaintance, however, object to getting their hot drinks in a cup which feels cold.
There is, of course, a whole field of psychology devoted to priming effects, such as the fact that being offered a physically warm cup, tends to create a ‘warmer’ atmosphere in meetings.
So today’s invention is a normal vacuum-insulated cup (white) embedded in a water jacket (orange). Filling the jacket to different heights, and with water at different temperatures, allows the host to provide a longer lasting hot drink in a cup whose temperature can be set almost independently.
