Himalayan porters

One of the more unsettling sights you see while trekking in Nepal's Khumbu Valley is the steady stream of porters carrying extraordinary loads on their backs. There are no roads, and no transport other than yak – small planes land at airstrips lower down the valley, but higher up, they're strictly for emergencies only. So these human white vans keep the trekking lodges, the local markets and the wealthy teams at Base Camp supplied with food, drink, construction materials and other essentials.

The porters – small, wiry and weathered – have straps across their heads to take some of the weight off their backs, and small wooden walking sticks that double as bottom rests. Bent almost double, they trudge past, one tiny step at a time.

We saw mountains of toilet roll, sheets of plywood, crates of beer, roll matting, plastic basins, lemon drink, kerosene, enormous wooden planks as large as a crucifix, plumbing pipes 12 feet long and, once, a generator. Most wear flimsy plimsolls or sandals. One person had bare feet. The terrain is rough, the altitude punishing, and the mountainsides steep.

But the larger the loads, the better the pay. So it makes sense to carry as much as you can, goes the logic.

Some loads are more lucrative than others. These blue plastic barrels are toilets headed for Base Camp. Lined with a plastic bag, topped with a Western seat and placed inside a tarpaulin, they make for a surprisingly pleasant loo-going experience, considering.

A porter carrying a full barrel of poo will earn 150 rupees (about £1.20) per kg. At 60kg per barrel, that's 9,000 rupees – a good wage in Nepal. Any porter lucky enough to get the gig overseeing the transportation of an entire Everest expedition's excrement for three months can earn $2,500.

Struggling with my own meagre backpack, these porters seemed superhuman – and medieval. But they brought the Everest experience into sharp relief. For every rugged, moneyed mountain climber seeking glory on the summit, there's a porter who has to has to carry their shit back down the mountain. And there's very little glamour in that.