How to prevent diseases caused by hot and cold weather?

In fact, now, especially at the turn of spring and summer, the weather in many places is actually cold and hot for a while, and then it suddenly rains. This situation is very easy to happen. Then, in view of this phenomenon, the most important thing is that we need to improve our body's immunity, because when your immune system is improved, just like the wall of your house is getting higher and higher, it is naturally difficult for thieves, which is what we call diseases, to invade your body.