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A water filtration bottle eliminates the endless stream of plastic bottles that line Everest Base Camp trails and saves roughly USD 150 over a three-week trek when lodges charge NPR 200-300 per liter above 4,000 meters. The LifeStraw and Grayl systems both handle the giardia and bacterial load in Nepal's streams, though neither filters viruses if you are drinking from sources near settlements. Most trekkers refill from lodge taps or designated safe sources rather than streams. The environmental argument is straightforward — the Khumbu alone generates an estimated 50 tons of plastic waste annually, much of it water bottles.
Cash becomes non-negotiable above Namche Bazaar where the last reliable ATM sits at 3,440 meters. Lodges, meals, and porter tips all require rupees. Cards work sporadically in Namche but nowhere higher. Budget NPR 3,000-4,000 per day for lodging, meals, and incidentals on standard routes, more for Annapurna Circuit's longer duration. Carry small denominations — a NPR 1,000 note can be difficult to break in a village teahouse. Toilet paper disappears from lodge supplies above 3,500 meters. Bring your own or purchase in Namche before ascending. A single roll compressed in a dry bag lasts two weeks for most trekkers.
Speaking of dry bags, a 20-liter roll-top bag keeps electronics, documents, and sleeping bag liner protected when porters strap duffels to the outside of baskets during monsoon-adjacent months. Nepal's weather shifts fast — a clear morning at Tengboche can turn to horizontal sleet by noon.
First aid supplies worth discussing with your physician before departure include altitude medications, antibiotics for gastrointestinal infections, and blister management supplies. CIWEC Clinic in Kathmandu stocks Western-standard medical supplies if you need to restock before a trek. Himalayan Rescue Association posts doctors at Pheriche (4,371m) and Manang (3,540m) during trekking seasons.
Thamel's rental shops line Tridevi Marg and stock boots, sleeping bags, down jackets, and trekking poles at USD 2-5 per item per day. Quality varies wildly. North Face and Mountain Hardwear items are frequently counterfeit — stitching fails, zippers jam, insulation clumps after three days. Boots represent the highest risk since a blowout at Kala Patthar cannot be repaired. If you are renting boots, test them on a three-hour Kathmandu valley day hike before committing. Sleeping bags rated to -10°C suffice for standard lodge treks through November. Everest Base Camp in October requires -15°C minimum. Down jackets worn in Kathmandu's 25°C heat look absurd but make sense — you are testing the zipper, checking arm mobility, and confirming it fits over your other layers before you need it at Lobuche.