The annual "Polar Bear" swimming season has arrived again in China's northeastern city of Harbin. Hundreds of "polar bear" swimmers plunged into an icy swimming pool on Tuesday.

The two-day contest has attracted brave swimmers from all over the country.

The swimmers faced minus temperatures to jump into a pool carved out of ice from the Songhua river. "Polar bear" swimming is traditionally popular in China's northeastern areas, where the weather is very cold.

The winter temperature can go as low as minus 35 degrees Celsius. It's especially popular amongst the elderly and retired as it's believed to improve circulation and benefit health. It's also said to increase the level of mental awareness,release stress, remove aches and pains, increase vitality and keep skin looking younger - and of course, an overall feeling of well-being.