I know Miss Li Fengjun, and my uncle is studying Miss Li's course. Uncle, he used to be afraid of the cold and his hands and feet were often frozen in winter. After knowing the knowledge of health preservation, my uncle pays great attention to tonic and conditioning in winter, and also cooks ginseng soup to drink. He seldom eats cold things like watermelon, cantaloupe, beer and grapes now. He takes proper exercise every day and soaks his feet with hot water at night. Now uncle's hands and feet are not so stiff and cold after getting up.