Climate: the Mongols and their horses were highly adapted to the dry and cold climate of the steppe and Siberian forests. Heat was tolerable for them， but humidity and wetness were far more troublesome. When the Mongols invaded southern Song，they suffered severely from diseases like dysentery， cholera， and malaria， as well as simply from the heat. Even the Northern Chinese had significant health problems fighting in the South under various Chinese dynasties.
#我在岛屿读书#近日读吕思勉先生的《中国通史》一书，读到南宋崖山海战一章，突然想到了一个问题，面对蒙古铁骑，南宋为什么能够支撑那么久，真的是因为南宋的军事力量十分厉害吗？由此便衍生出下面的一些文字。吕思勉：中国近现代史学界的泰斗，名列中国四大史学家之中。
在蒙古帝国攻灭的国家中，以南宋抵抗的时间最长，长达四十余年。南宋之所以能够抵抗蒙古/元朝达四十多年，一方面与南宋军民依托地形和坚城顽强抵抗有关，而另一方面则是因为蒙古自身出了各种各样的问题，所以才给了南宋苟延残喘之机。
