In ancient winter, a lot of ice was buried in the underground/cellar, and it was taken out in summer to cool the royal family. Besides using ice cubes to cool down, imperial doctors in the palace also prescribe Chinese herbal prescriptions for relieving summer heat, such as Elsholtzia Decoction and Xiatang, as well as pills such as Elsholtzia Pill, Huoxiang Zhengqi Pill and Qingshu Yiqi Pill. It has been recorded in the Qing Dynasty that the ice cubes in winter were kept in the cellar until the next summer. However, the preparation of diet is also the main way for the ancients to cool down and keep fit.