During the Korean War, communist Chinese "volunteers" intervened in November 1950 during a brutally cold winter. They surprised and mauled numerous American, South Korean and allied United Nations units (See film of the aftermath here.) But the Chinese also faced devastating casualties from both American air power and the weather. Many thousands were anti-communist Chinese forced into battle by the PRC, often without proper clothing or even, in some cases, weapons. US forces learned enemy soldiers sometimes wore only the equivalent of tennis shoes with clothing of limited protective value, even as they marched long distances in the snow and holed up without moving during the day to maintain secrecy and avoid attack. Wartime reports include accounts of American troops tracking Chinese soldiers via the blood their feet left in the snow.
US psychological operations campaigns took advantage of this situation throughout the war by urging Chinese and North Korean soldiers to surrender before they froze to death. Tens-of-thousands of Chinese and North Korea troops surrendered for this and other reasons. The desire of many of them, once under American control, to avoid being sent back helped extend the war for almost two years as China, North Korea and their Soviet ally tried to have them forcibly returned to communist control.
How China Never Returned or Accounted for American POW/MIA In Its Hands During the Korean & Cold Wars -- Then Cheated the Pentagon in Recent Years Out of $$$ for Files on the Missing Men
The POW Investigative Project, a non-profit founded by the Executive Producer of Need to Share News, uses crowdsourcing in Chinese and other languages to seek answers on the fate of missing American heroes.
The men below were known or suspected to be in Chinese hands but never returned or accounted for (there are many similar cases involving North Korea and Russia/Soviet Union). Click on their photos for more information.