I came across this on Dan Pink's blog.
This caption on a coffee cup is supposed to serve as a warning sign to caution people that the coffee is hot and care must be taken to avoid burns.
The problem I see is that noone holds a full cup this way and by the moment when the cup is almost empty the coffee is not that hot and is more or less safe. While the cup is full it is held by gripping from the side and then the hand obscures the caption. Plus the text is so small it drags almost no attention.
IMO it'd be better to place the text closer to the cup top and use a twice as large font.
How useful is the warning implemented the way it is shown on the photo?