Given the hot weather, stick to light fabrics such as cotton and linen. They are great in so many ways as its lightweight, easy to wash and dry quickly. Pack sufficient cotton t-shirts, shirts, dresses, skirts, shorts and trousers to keep you cool and comfortable. Also, try to make sure they are in light colours such as white and pastel, as darker colours tends to absorb more heat. When visiting temples, both genders need to dress modestly and cover both knees and shoulders. A shawl will also come in handy to protect your hair and head from the sun. Showers can occur at certain times of the year, so a lightweight raincoat or umbrella will also come in handy. And of course, don't forget to pack a couple of pairs of swimwear to make use of the pool available to you on the cruise, such as the Mekong Kingdoms cruises.