Flying to Peru with a full set of mountain equipment for one trek makes little sense, and Cusco knows it. There are rental shops on almost every street in the centre.

The useful question is not whether to rent but what. Some things are fine to rent, some are a false economy, and one is almost always a mistake.

Check what your operator already includes

Do this before you rent anything, because it is where most wasted money goes.

On an organised trek the tent, the sleeping mat, the cooking equipment and the group gear are included. Many operators also include a sleeping bag, or rent one to you directly at a reasonable rate.

Ask for the list in writing when you book. Turning up in Cusco with a rented mat you did not need is a common and avoidable annoyance.

Worth renting

Sleeping bag. Bulky, heavy in a suitcase and only useful for a few nights. Rent it, but see the warning below about temperature ratings.

Trekking poles. Awkward to fly with, cheap to rent and genuinely useful on the long descents. One of the clearest cases for renting.

Down jacket. Takes up a third of a suitcase and you will wear it on three evenings. Easy to rent and usually in decent condition.

Duffel bag for the porters. Operators often provide one, and if not it costs very little to rent.

Headlamp. Rentable, though they are small enough that bringing your own is just as easy.

Bring from home, whatever it costs you in luggage

Boots. This is the one that matters. Never rent boots. Blisters on day two of a four-day trek ruin the trek, and blisters come from boots your feet do not know. Bring yours, broken in over weeks of walking.

Socks. Technical socks, several pairs, yours. They weigh nothing and they protect your feet more than people realise.

Waterproof jacket. Rental shells are often tired and no longer actually waterproof, which you discover at the worst moment.

Base layers. Anything worn against the skin is better brought from home, for obvious reasons.

Personal medication and your own daypack. Both are things you want to be familiar with.

The sleeping bag trap

This deserves its own section because it catches people every season.

Campsites on the Inca Trail, Salkantay and Lares are cold, and on the Ausangate circuit they are very cold: below zero almost every night of the year.

Rental shops advertise bags by a temperature number that is often the extreme rating rather than the comfort rating. The difference between the two can be ten degrees, and it is the difference between sleeping and shivering until dawn.

Ask specifically for the comfort rating. Ask for minus ten or lower if you are doing Ausangate. And look at the bag before you accept it: a flattened, thin bag has lost its loft and will not perform at whatever number is on the label.

Practical points when renting

Rentals are charged per day and most shops ask for a deposit or hold your passport. Leaving a passport is common practice locally but you are not obliged to accept it; offer a copy plus a cash deposit instead.

Inspect everything in the shop. Zips on the sleeping bag, tips on the poles, seams on the jacket. Photograph anything already damaged so it is not charged to you on return.

Rent the day before you leave, not the morning of. Shops open late and a queue at eight in the morning when your bus leaves at nine is a bad start.

And compare two or three shops. Prices on the same street vary more than you would expect, and so does the state of the equipment.