Hi. The heat-resistance is achieved through the chocolate. It is safe for consumption. In fact many chocolate companies like Cadbury and Hersheys are making heat resistant chocolates so that it can withstand climate changes. Other concerns about sugar intake and preferences are indeed an issue. But then coffee itself isn't very healthy. This concept is still in the experimentation phase. It is a start to a new idea of edible packaging which will most likely be modified and improved in the future.