1 / 4   Border guards patrol in Tahe County, northeast China’s Heilongjiang Province, at minus 33 degree Celsius on January 28, 2018. /CFP Photo

2 / 4   They inspect on foot along the border between China and Russia to maintain regional peace and harmony. /CFP Photo

3 / 4   Icy frost is formed on their eyelashes, facial masks and hats. /CFP Photo

4 / 4   These soldiers remain vigilant despite the harsh weather. /CFP Photo