I literally hadn't heard of this brand until this comment, but I figured it was worth pointing out that their "layer of insulation" is a bit more complex than i

I literally hadn't heard of this brand until this comment, but I figured it was worth pointing out that their "layer of insulation" is a bit more complex than it might seem at surface level, being a phase-change insulator. They claim that it changes phase right around the 63 degC mark (which, again, is claimed to be the sweet spot for where most hot beverages are enjoyed). Therefore, a hot drink will quickly move to that temperature when the poured liquid is above that transition temp (the liquid-phase insulator being a good conductor), and then stay close to it after dropping below the transition point, when the solid insulator re-forms and stops conducting heat well. If true, I think it's a really neat application of high-tech materials science in everyday life. [1] https://joeveo.com/pages/the-temperfect-mug https://joeveo.com/pages/the-temperfect-mug (see "Details for the Technogeek)