Study on the Yong Han Won Han(用寒遠寒) and Yong Yul Won Yul(用熱遠熱) of Yuk Won Jung-Gi Dea Ron(六元正紀大論)
Five elements motion and six kinds of natural factors influence not only human disease but also difference of medicine effect. Because the climate of summer is very hot, that is easy to increase the properties of hot medicines, a doctor must be careful to use it in summer. Also the climate of winter is very cold, that is easy to increase the properties of cold medicines, a doctor must be careful to use it in winter. But in the certain conditions to use diaphoretics or purgatives, in spite of that regulation a doctor can use them.