Extreme Winter Swimming from Around The World Introduces 'Ice Hugging', 'Ice Plunging' and More (PHOTOS):

Winter swimming is a surprisingly popular pastime. All around the world, adventurous (or crazy?) people strip down to their bathing suits and dive into icy waters.

Why do people risk hypothermia to go ice swimming?

"Winter swimming, or submerging oneself in freezing water, has religious and cultural roots," Marianne English reported in Discovery News. "In Eastern European countries such as Russia, many practice the activity to observe the Epiphany, or a holiday celebrating Jesus' baptism. During this time, followers believe water from lakes and rivers is spiritually cleansing."

Some Japanese people also view ice swimming as spiritually beneficial. Earlier this month at the Teppozu Inari shrine in Tokyo, men wrapped their bodies around giant ice blocks as they bathed in frigid water, as part of a Shinto ceremony to purify their souls and wish for good health in the new year, reported Reuters.

Other people dive into frigid waters to make a political statement. British explorer and endurance swimmer Lewis Gordon Pugh, pictured above, dove into the North Pole to "highlight the impact of climate change," said Reuters. He swam one kilometer in 35-degree F water, "wearing only briefs, cap, and goggles."

It's important to practice winter swimming safely, cautioned Marianne English in Discovery News. "Even the most experienced swimmers run the risk of hypothermia," she said, which is why it's important for swimmers to limit themselves to short exposure. Most newcomers to the activity limit their exposure to a few seconds, while others who have more experience may stay in for a minute or two."