China's first storybook made with temperature-sensitive ink aims to raise awareness of global warming. Video filmed in Changsha City in southern Hunan Province on May 25 shows temperature-sensitive ink being applied to the book, "Penguin Frozen Storybook." In another clip, the writing and pictures in the "frozen storybook" is fading away gradually as the temperature increases from -10C to 20C. The book aims to mimic the way glaciers melt. It has to be frozen for 15 minutes in a fridge before being ready to read.