It was so cold during our trip to Beijing and Chengde that lakes and rivers were frozen over. While visiting the summer palace in Chengde, there was a man who had a crate with metal blades on the bottom. He would propel himself on the ice with it using two iron rods.
Of course for a price you could rent his unusual form of transportation. One of the members of our group took it for a spin, and then let Tim try it out. She didn't move fast, but she seemed to have fun.