Workers will work in bitter coldness, with temperatures as low as -30 degrees celsius, on the frozen Songhua River for 20 days. The ice bricks they collect will be used as raw material for the China's biggest winter gala – the Harbin International Ice and Snow Festival, which will start on January 5. 

The annual event attracts visitors from home and abroad every winter. Up to 180,000 cubic meters of ice is expected to be used at the event, which features striking ice sculptures. Most of the ice blocks taken from the Songhua River will be used in construction for the festival, where buildings of ice will be illuminated by colorful lights.