This is pretty awesome. I’ll bet McDonalds wishes they had these back when that old woman sued them for hot coffee.
Not only do these lids change color to bright red when the beverage is hot there is also a sealing indicator that shows whether or not the lid is securely attached properly to the cup. It will be red while securing it and until the entire rim is brown, the lid is not secure. I know when coffee or whatever is hot but I would like to see coffee shops use these if for no other reason to let me know they put that lid on tight!