汗流浃背 — “To sweat profusely”

The idiom "Han Liu Jia Bei" (汗流浃背) originated from a story during the Western Han Dynasty. Huo Guang, a powerful general and regent, was a trusted minister left by Emperor Wu to assist the young Emperor Zhao. After Emperor Zhao's death, Huo Guang chose Liu He, King of Changyi, as the new emperor. However, Liu He proved to be an unfit ruler, indulging in revelry and neglecting his duties.

Huo Guang, deeply troubled, secretly consulted with other high-ranking officials to depose Liu He and enthrone a more suitable successor. When Huo Guang dispatched Tian Yannan to inform Yang Chang, the Chancellor (丞相), of their decision, Yang Chang, a timid and indecisive man, was utterly terrified. Upon hearing the grave news, he became so frightened that he "sweated profusely, soaking his back" (汗流浃背), unable to utter a coherent word, only nodding vaguely.

Yang Chang's wife, who was the daughter of the famous historian Sima Qian, possessed great courage and insight. Seeing her husband's hesitation, she urged him, "State affairs are not to be trifled with. The Grand General has made his decision; you should act quickly, or disaster will surely befall us." Although Yang Chang paced back and forth, he remained irresolute. When Tian Yannan returned, Sima Qian's daughter bravely met him and assured him of her husband's compliance with Huo Guang's wishes.

Tian Yannan reported back to Huo Guang, who was pleased. Subsequently, Yang Chang, along with other ministers, formally requested the Empress Dowager to depose Liu He. The Empress Dowager issued an edict, removing Liu He from the throne and establishing Liu Xun, Emperor Wu's great-grandson, as the new emperor, known as Emperor Xuan. This event solidified the idiom's meaning, describing someone sweating profusely due to extreme fear or anxiety. It is now also used to describe sweating heavily from physical exertion or heat.