This tropical fruit, native to Southeast Asia, is perfect for the summer. It has leathery red skin and juicy, translucent white flesh. These delicate fruits contain approximately 82% water. They are rich in vitamin C, which helps strengthen your immune system during the hotter months, when dehydration can make you more vulnerable to illness. Lychees are also a natural source of copper, which plays a crucial role in energy metabolism. You can eat them fresh or refrigerate them for a refreshing twist.