Fan death is a belief widely held in South Korea alone which claims that sleeping in an enclosed room with a fan on is a potentially fatal activity. The exact reason for why this can kill you is unclear, but theories range from the fan blades chopping up the oxygen molecules rendering the air unbreathable to the fan chilling the air to dangerous temperatures and killing through hypothermia.

In actuality none of these theories hold up to scientific scrutiny and fan death does not exist, however, cases are frequently reported in South Korea every summer even when more obvious signs of death are present, such as gunshot wounds and profuse bleeding.