If you wish to swim in a water body
Cold Himalayan weather
- Water with salts is essential in (sub)tropical Indian weather, even in the mountains. You'll easily go through 3 litres in the hot tropics.
- Headlamp is for if and when it gets dark. You might not plan to stay out in the dark, but getting lost in the dark is not fun. Prefer a headlamp over a torch, it keeps your hands free. Decent, affordable headlamps are available locally.
- Clothing: prefer hiking trousers over jeans. If you're going to an area with thorny plans, prefer full-length trousers over shorts.
- Footwear: I prefer hiking sandals in hot weather (and in rainy weather too) and ankle-length hiking boots in the Himalayas. Don't take your Nikes or Pumas on hikes, you'll destroy them. Hiking sandals are better in the rain because your fanciest waterproof hiking shoes will become a pain if they get wet from the inside. Hiking sandals will dry out very quickly, and you can still walk in them quite comfortably while wet. Shoes will get wet from the inside when the water enters from the top. And waterproof shoes take at least half a day to dry out, and they aren't comfortable to walk in while they're wet. It's like carrying an annoying personal puddle with you. If you really want to keep your feet dry, choose gumboots/wellies.
- Helmets/hats: I find my climbing helmet useful for protecting my bald head when pushing through dense thorny bushes. Usually not necessarily in the Himalayas, though.