A tracksuit is useful for wearing in the evening and when cold for sleeping in. A waterproof poncho is needed in areas that are prone to rainfall. A wide brimmed hat is also a good thing to take to keep the head and neck from being burned by the Sun's rays. Some hikers wear gaiters to prevent seeds and other things from getting entwined in their socks. A pair of cassual shoes or sandals is a good idea for around the camp after the day's hike.
Sandals are also a good idea to take along to wear while crossing rivers.
If one is planning to cross a major river, a large, heavy-duty plastic bag is a useful item to have along to float your backpack across in. I find it a good idea to enclose clothes, sleeping bag and food in plastic bags before putting them into my backpack as this acts as an additional protection against accidental wetting. An essentual part of any hiker's equipment is the First Aid kit. Ask your hike leader, pharmacist and general practitioner for guidance. The consensus of opinion these days is not to carry snake bite anti-venum but to imobilise the casualty, bind the wound tightly starting at the centre of the wound working outwards and send for help or get the patient as quickly as posible to the nearest doctor.