> my daily use for it was checking if the coffee was cool enough to drink
My wife has the same issue with hot coffee which drives me a little nuts. She uses a normal mug most of the time. Because she isn't certified in coffee temp detection like I am; she waits and waits, gets distracted, and eventually it becomes too cold. So she reheats it in the microwave, usually to the point where it's too hot, and that cycle continues after it gets too cold again. She's probably reheated coffee in the microwave up to 4-5 times a day at times. It's hilarious and ridiculous. As an engineer, admittedly, I enjoy the hilarity so much I'm not sure if I care about it being resolved!
The issue is two-fold:
1) She lets the coffee hit the outermost parts of her lips and subjects herself to getting destroyed by the high temp lol. I don't understand why this is so difficult for people. Your outermost lips are more sensitive. Don't do that. You don't attack hot coffee like it's a fine bourbon. Also you can feel the temp and steam to know not to even attempt based on your preference and tolerance.
2) She isn't sitting at a desk consistently like most of us. She's everywhere in the house and then leaves, and her coffee intake isn't a priority like many of us.
If I put her coffee in a stainless steel mug with a lid, then it takes too long to cool to her temp. She leaves the lid off to cool and then forgets about returning to it in time. And she doesn't end up drinking the coffee because it becomes too cool. So now she would have to transfer to a microwaveable mug to reheat and start that cycle so she doesn't even bother. If I'm prepping her a roadie coffee, I must pour it, leave the lid off for a period of time and then place it back on so she will attempt drinking it in time in the car to commit to it. If it's too hot, she will more than likely just abandon it and not check back in before we reach our destination.
I got her an Ember mug so she can read the actual temp and control it. But it's not dishwasher safe of course. So she doesn't tend to use it. And from the fresh brewed carafe to the Ember still is too hot, unless the lid is off for some time like the stainless steel mug, lol.
The ideal mug for her would thus be an Ember mug that is dishwasher safe and thus have some sort of twist mechanism to disconnect the battery and status/controls portion from the core mug function. And probably have a vent mechanism on the lid (maybe a double pop on the Ember lid to vent more?) to more quickly get the temp down from initial temp, as the heated mug portion can ensure the set temp is hit anyway.
Someone please build that and save me! Or don't, and I'll enjoy the entertainment derived from the struggle. :)