DeLoreans aren’t the only modern marvels. Heat changing mugs are a marvel in their own right – especially if you put yours in the cupholder before you go all the way back to 1955. And then attempt to show how it works to somebody. It’ll blow their mind. We don’t recommend doing that, though. It took a lot of ingenuity for Marty to get back the first time, and we’re pretty sure your coffee would be cold by the time you arrived.When this baby hits 88° F, you’re gonna see some serious stuff… Referenced in Ready Player One.