I remember buying a hot chocolate of that brand from Walmart. There was a plastic/foil thing on the bottom of the can, you pressed it inwards, and the can would

I remember buying a hot chocolate of that brand from Walmart. There was a plastic/foil thing on the bottom of the can, you pressed it inwards, and the can would heat up inside a minute or so. I remember taking one of those with me when I had to work outdoors, it was quite nice. Only saw them for a month or two. I wonder what happened?