Li Hongjie and his brother began ice-fishing on the Nen River in the Chinese city of Qiqihar five years ago. The river is in Heilongjiang province, the most northeastern part of the country, where the average winter temperature is minus 30 degrees Celsius (-22°F). Ice in the Ren River can freeze to nearly one metre (3ft) thick, making their fishing trips unbelievably tough and challenging. The brothers began posting videos of their extreme ice-fishing adventures on social media four years ago…