Once your planning is done, the next step is to make sure you have all of the supplies and equipment you will need for your Great Wall adventure. Some things can be procured in China if you prefer. This can reduce the load you need to carry traveling to China. Sometimes you can save some money this way, at the cost of some time and effort in China. The other choice is to purchase everything before you leave for China so you won't have to spend any time or effort on buying supplies and equipment once you reach China.
Selection of hiking equipment is a very involved subject with many differing, strong opinions. Because hiking is such a widespread and popular activity, many different solutions are available. It's important to remember that there can be several very satisfactory solutions to a problem, and just because someone is totally convinced that their way is best doesn't mean that there isn't another solution of equal merit. Just check a popular hiking location like the Appalachian Trail and you will see many highly-experienced hikers using vastly different gear. What's important is what works for you, so listen to other people's opinions and then make your own choices.
The specific clothing you will need depends on the weather. In the mountains, weather can be quite cool at night even when it's warm or hot in the daytime. For this reason, multiple layers work well and provide greater versatility than fewer, heavier layers.
How much hiking clothing you will need depends on how extensive a Great Wall hike you're planning. For a simple day trip to the Great Wall, normal travel clothing is adequate, but it's good to be familiar with the outdoor clothing discussed here. You may well find it's very useful for travel in general even if you're only going to spend a limited amount of time walking the Great Wall.
Hiking calls for synthetic materials like nylon and polyester. Cotton does not insulate when it's wet and therefore is not appropriate for serious outdoor use.
For longer hikes, try to use clothes that dry quickly so that you can carry fewer spares.
A good base layer can be worn by itself in warmer weather and underneath other layers in cooler weather. A lightly insulated base layer is a good compromise in comfort, weight, and bulk.
A warm middle layer like fleece is useful in colder weather but can be omitted in warmer seasons. Some people prefer to wear a warmer base layer and omit the middle layer in cold weather. This requires a good outer layer (jacket).
Shirts for hot weather wear should be lightweight, breathable, and ventilated. Long sleeves with roll-up ability and stand-up collars offer good sun protection. Nylon and polyester are good material choices.
Jackets are essential in cold weather. Fleece is good for mild cold but insulated jackets are better for winter conditions. Consider a windproof jacket for the best protection from the wind you will encounter on exposed mountain ridges.
Rainwear is most useful during the rainy summer season but many people forego rainwear altogether. A good compromise is a lightweight breathable rain jacket that will work in cool dry weather as well. Another good alternative is a water-repellant jacket rather than a waterproof one. This will breathe better for use in dry weather but still provide some protection from rain.
Socks are very important for hiking. You want breathable, durable socks with the right amount of cushioning – not too little and not too much. Hikers have a wide variety of sock preferences. Some like thin nylon dress socks. Others prefer wool socks. Socks that dry quickly allow you to carry fewer pairs. Again, avoid cotton.
Underwear is a very personal choice, but do make sure to use underwear intended for hiking. You can get comfortable, lightweight, anti-microbial, quick-drying underwear in many styles from many manufacturers.
Gloves are useful in cold weather and also to protect your hands if you're going to be hiking in thick brush.
A warm hat is also useful in cold weather, and a sun hat is useful for those with sensitive skin. Many people find that sun hats keep them more comfortable in hot, sunny weather too.
Sunglasses are also very helpful for protecting your eyes and reducing fatigue in sunny weather. Polarized sunglasses are useful for outdoor activities.
The first question to be answered about footwear is whether you want shoes or boots. In general, boots provide more ankle protection while shoes are lighter weight and cooler. Compromises are available with low-cut boots. Ankle protection is very important when walking the Great Wall because the surface can be both uneven and loose.
The weight of your hiking shoes is very important. Because you are lifting them over and over again, lightweight shoes can improve your ability to walk further with less fatigue, while heavy shoes can tire your muscles and waste your energy. Sometimes lighter weight shoes are less durable than heavier shoes of comparable cost, which implies that lighter weight shoes that are still comfortable and durable cost more. This may be true in general, but there are many good lightweight shoes available for fair prices.
The quest for light weight leads many people to wear low-cut shoes like lightweight hiking shoes and trail running shoes instead of hiking boots. You must compromise either safety or lightness, although, again, some shoes are lighter weight than others that offer similar protection. If your ankles are relatively strong, your need for boots is reduced.
Another consideration is whether or not waterproof shoes or boots are needed. It's important to realize that waterproof shoes do not breathe and release perspiration like other shoes and therefore can be hot and uncomfortable. This excess heat can lead to blisters. Wearing non-waterproof shoes is reasonable for walking the Great Wall, especially if you wear good, synthetic, fast-drying socks.
Whatever type of footwear you choose, it's crucial to make sure of a good fit. Shoes should be tight enough to prevent rubbing, which leads to blistering. But they must not be too tight, either. Make sure your shoes are the proper width as well as length and be aware that feet tend to swell somewhat (perhaps half a shoe size worth) as the active day of walking progresses.
Some people prefer aftermarket insoles to those provided in the shoes or boots they buy. Insoles are available in varied materials, thicknesses, and densities. They can contribute to comfort level on long hikes and they can also improve the fit of your shoes as well. New insoles can also extend the life of shoes that are old and have worn insoles but are still in good outer condition.
For all but the shortest walks, you'll need a backpack or other carrying gear. What type and size of carrying gear is dictated by what you will need to carry on your Great Wall walk. For a very short walk on the Great Wall, you really don't need to carry anything, so you don't need any kind of a pack. For anything longer than a few hours, you will need to carry water and possibly food, and so you will need to carry some kind of pack. For longer walks, the list of things you will need to carry begins to grow, and along with it the size of the pack that you will need. Determine what you will carry on your Great Wall walk and get a pack to match. For a day hike, you can use a waist pack or a small backpack, known as a day pack. For a walk of two days or so, a small backpack will suffice. And for a longer walk, a larger pack is called for.
Backpacks can be categorized by their frame design: external frame, internal frame, or frameless. If you're doing a very long hike and carrying a lot of gear, you may want to consider an external frame backpack. Otherwise, you can get by with a lighter-weight internal frame or frameless pack. The pack you choose should be the lightest weight pack that has the carrying capacity (weight and volume) you need. It's an important compromise; get the lightest-weight pack you can, but get one that's comfortable to carry too. Ask around about what other people use. Once you have identified a pack you like, try to test it with an all-day hike carrying at least the maximum amount of weight that you expect to normally carry. Make sure your pack fits you properly. The weight in your pack should be divided between your hips and your shoulders in a manner that feels balanced and comfortable.
Many different features can be found in backpacks. Some of them are gimmicks; others are genuinely useful. One very useful feature is a ventilated back panel that keeps your back cooler.
The most important, and probably the heaviest, thing you will need to carry is water. How much water you need depends on how hard you're working, how long you're walking, and on the weather. You could need up to four liters (one gallon) per day in extreme conditions.
There are two basic choices for carrying water: a refillable bag with a hose that fits in your backpack, known as a hydration system, or bottled water.
Hydration systems keep a tube handy for you to sip from at regular intervals, which is good in encouraging you to drink regularly. But they must be cleaned periodically, they can develop leaks, and the tubes can be prone to freezing.
Water bottles are simpler to manage but harder to use, as you must remove the bottle from a pocket in your pack to use it, and you must replace it after each use.
If you're using water bottles rather than a hydration system, you may want to consider reusable drink containers rather than relying on disposable containers purchased on site. Boiling your own water and allowing it to cool overnight is a good way to lower costs, reduce pollution, and save weight. You'll need large (1-liter) water containers for this purpose. Be sure your containers can withstand boiling water. Large mouths on your water containers make them easier to clean. For shorter hikes, it may be simpler to buy bottled water in disposable bottles.
If you're planning on sleeping on the Great Wall, you will need a sleeping bag. A huge variety of sleeping bags are available. They differ in weight, size (bulk), insulation value, and, of course, cost.
One choice you will make is the insulation type: down or synthetic. Down provides the best ratio of high insulation value at low weight. But it must be kept dry. Synthetic is slightly heavier, but insulates even when wet and costs less.
Sleeping bags are rated at various temperatures. The lower the rating, the warmer and heavier the sleeping bag will be. The season during which you will be sleeping on the Great Wall relates to what sleeping bag temperature rating you will need. If you're willing to sleep with clothes on, including a jacket, you can get by with a lighter sleeping bag.
A bivouac sack is a good alternative to a sleeping bag in many situations, especially if it will not be used regularly. Carrying a bivy sack will give you the option of sleeping out if the situation arises, even if you are planning to sleep in a hotel or guest house. Check into bivouac sacks and consider using one instead of a sleeping bag and tent.
Along with your sleeping bag, you will also need a sleeping pad. Sleeping pads provide two basic functions: insulation and padding from the cold, hard ground. You will choose between inflatable and non-inflatable sleeping pads. Remember that inflatable pads can leak due to damage, and it's a good idea to carry a repair kit. They do provide good insulation and padding.
Foam pads can be used as an internal frame on a frameless backpack. You might have to trim your foam pad to fit your pack properly.
A wide variety of tents are available. In general, the more money you're willing to spend, the lighter weight you can get. It can be windy on the Great Wall, so make sure your tent is sturdy. Freestanding tents are convenient on hard surfaces such as the wall and reduce ground damage.
A tent is a customary part of a hiking trip, but you can easily hike and sleep on and around the Great Wall without one if you prefer. This can save quite a bit of weight.
While you're researching tents you'll also find out about alternatives such as tarps and hammocks. These are great alternatives for hiking trips in general, but on the Great Wall, they may be totally unnecessary.
Long-distance hikers very often use trekking poles, or walking sticks. They have many advantages, and on the Great Wall, these advantages are even greater. Trekking poles transfer some of the effort of climbing from your legs to your arms. They improve your balance by giving you additional points of contact. They reduce the strain on your knees when going downhill. And they can be put to many additional uses. Defending against aggressive dogs and other animals is an important one. They can also be used as tent or tarp poles, laundry hangers, and much more.
It is important to have sturdy, trustworthy trekking poles. Most trekking poles are adjustable and collapsible, so they must have a locking mechanism, and the locking mechanism needs to be secure as possible. The Black Diamond brand trekking poles have some of the most reliable locking mechanisms available.
It takes practice to get used to using trekking poles. You should try them on test hikes to make sure you like them and you know how to use them properly. Learn how to put your hands through the straps properly (up and through from the bottom) in order to let the straps bear weight rather than having to grip the handles of the trekking poles too tightly.
Trekking poles can be an inconvenience. They occupy your hands, which you might need in order to hold onto things to keep your balance, to take photos, to hold your GPS receiver, and so forth. Trekking poles can present a major hazard if you do fall. Metal tips on trekking poles can also cause surface damage and are therefore not allowed at certain cultural heritage sites such as the Inca Trail in Peru. Therefore, be very careful not to damage the Great Wall with your trekking poles.
Most airlines will not allow you to carry trekking poles onboard an aircraft. They look too much like weapons. Therefore, you will need to place them in checked baggage.
If you aren't going to bring rain gear such as a waterproof jacket on your hike, you might consider an umbrella. The longer your Great Wall hike, the greater the chance that you will encounter some rain. An umbrella can be a good substitute for rain gear. You can get a lightweight umbrella from hiking supply vendors. Make sure yours is reasonably sturdy. Along with rain often comes strong and gusty wind on the Great Wall, which can quickly damage your umbrella.
If you're planning to walk on original parts of the Great Wall, you need navigation tools to be able to determine where you are, find where you need to go, prevent getting lost, and to be able to recover from getting lost.
Paper maps are the most reliable resource, but you need good maps and you must know how to use them. Finding good, detailed maps – especially topographic maps – is not easy. This is even more of an issue if you want to find a map in a language other than Chinese. They can be found online if you're willing to print them yourself. Maps can also be found in the major bookstores in Beijing and other large cities in China.
Many people eventually find out that a map with all of the features that are needed is nearly impossible to find. The solution is to make a map. One way to make a map using your computer is to take an online road map and add the features that you need. You will want to add the Great Wall, as this is often not available or not accurate on road maps. You might want to add foot paths. Latitude and longitude marks are also useful. If the map is in Chinese, you may want to add some place names in English or Pinyin (romanized Chinese). Making your own maps does require some effort, but you will end up with the exact map you need and it will be a pleasure once you get the opportunity to use it.
Along with paper maps, you will need a compass. There's no other way to determine direction than a good magnetic compass, and they are small, lightweight, and inexpensive, so there's little reason not to carry one.
You must learn how to use your paper maps and compass. Learn how to read a topographic map, including the meaning and interpretation of contour lines. Know how to track your location on the map as you walk. Learn how to use your compass. You should be able to orient your compass to geographic north. And you should know how to take a bearing, how to orient your map with your compass, and how to navigate with your map and compass. Learning these basic techniques will give you confidence and can save your life.
In order to use your compass accurately, you'll need to know the magnetic declination for your location. Generally, declination gradually increases along the Great Wall from west to east, from 0.75° W in Jiayuguan to 7.3° W in Shanhaiguan. In the Beijing area, it's about 6.5° W. Magnetic declination is about 0.3° E in Dunhuang, the westernmost significant Great Wall area, and 8.3° W in Dandong, the easternmost point on the Great Wall of China, on the Korean border.
GPS receivers are popular and convenient tools for navigation. They have so many advantages that any serious hiker should consider using one, and the Great Wall is an ideal place to use it. Consider a mapping GPS receiver that is designed for hiking or outdoor use.
Prepare maps and data for your GPS ahead of time. Like printed maps, GPS-based topographic maps of China are not easy to find. You may even want to select your GPS receiver based on what maps are available. Be aware that most GPS maps are in Chinese. Finding one in another language is even more difficult, but they can be found. Install your maps on your receiver and make sure they work properly. You will also want to prepare one or more GPX files for your GPS receiver that contains information you will want during your hike. This includes paths and points. Paths might include the Great Wall itself, roads, and trails. Points, also known as waypoints, might include specific locations you want to find, such as bookstores, bus stations, and landmarks.
If you're going to hike with a GPS, you'll need batteries. Most outdoor GPS receivers use standard batteries such as AA batteries. You will choose from disposable or rechargeable batteries. If you are doing a relatively long hike and you don't expect to have regular access to power for recharging batteries, you'll need disposable batteries. Lithium batteries have lighter weight and longer endurance, but they cost more than normal, disposable alkaline batteries. Lithium batteries are not easy to find in China, so you should bring them with you. If you can recharge your batteries every few days, consider using rechargeable batteries to reduce overall weight for a long walk on the Great Wall.
The Chinese government has some regulations about GPS maps that end up making GPS maps inaccurate. The location of the map is offset a varying amount and direction in varying places. The distance is enough to make hiking with one of these maps very difficult. Some GPS receivers in China correct for this problem, but they correct by offsetting your location to match the map rather than offsetting the map to the correct location, so they are not an ideal solution. It's very important to be aware of this problem and avoid these products. The best way to confirm that your map is accurate is to transfer a waypoint from a satellite image mapping program like Google Earth to your GPS and then check to make sure that the location on the map aligns exactly with the position you located on the satellite image.
Practice using your GPS on real hikes before setting off for China. Try to simulate as many scenarios as possible, including planned (like hiking to a given location) and unplanned (like retracing your steps if you get lost).
Many cell phones offer GPS software that finds your location based on cell phone towers rather than satellites. These work reasonably well in most areas, but they do depend on proximity to multiple cell phone towers for accuracy, and they may not offer all of the features of a dedicated GPS receiver.
If you're planning to use polarized sunglasses, make sure they are compatible with your GPS equipment. Polarized glasses make some GPS receivers difficult to read, while some people say they make it easier to see their GPS. Be sure to test this both in sunlight and in shade.
It's important to remember that cell phones and dedicated GPS receivers can fail. Do not rely on them solely. Whether or not you use a GPS, carry a paper map and a compass, and learn how to use them properly.
Walking the Great Wall will be one of the best photo opportunities you will ever experience. Great locations make for great photography, and few locations have the combination of attributes that the Great Wall offers. First, of course, is the Great Wall itself, a fantastic structure that seems to go on and on forever. Then there is the beautiful scenery, whether it's vast and wild ranges of mountains or pristine stretches of desert. Between the variety of Great Wall appearances and the different environments through which the Great Wall runs, there are endless possibilities for unique and outstanding photographs. Photo equipment is the one item that, while not technically needed, should absolutely not be left out on your Great Wall walk. Your photos will be your main souvenir from your adventure on the Great Wall and you will want them to look good.
The first choice you will make is whether to bring a video camera or a still camera. The Great Wall does not offer much motion, so the primary use for video is panning and zooming. Still photos are much more suited to Great Wall photography, so if you're planning to use a video camera, you'll want to bring a still camera too. Fortunately, most still cameras have reasonably good video capabilities, so for most people a single still camera fills the needs of both still and video photography.
If you're a professional photographer or a serious amateur, you probably already know what kind of camera you want to carry. SLR cameras offer the best quality and capabilities, but they are larger and heavier than other cameras. Along with their cameras, photographers usually want to carry a range of lenses, adding further to the size and weight of your camera equipment. The longer your Great Wall walk, the more of a burden your camera equipment will become.
Smaller cameras keep getting better and better in terms of both image quality and features. You don't have to give up on manual exposure methods, manual focus, high sensitivity, and low noise when selecting a portable camera. There are tradeoffs, but they are getting less significant every year.
Whether you are using a camera with a built-in lens or an interchangeable lens camera, your lens choice is very important for Great Wall photography. The primary specifications of lenses are focal length and aperture.
Focal length varies from wide angle to telephoto. Wide angle gives you a wider field of view, and telephoto gives you a narrower field of view, allowing distant objects to be photographed in detail. Focal length is expressed in mm, with wider focal lengths being smaller numerically. Focal length is compared using the equivalent of a 35mm camera since the size of the image sensor changes the effective focal length of a lens. For example, 24mm is a wide angle lens and 200mm is a telephoto lens.
Aperture is the amount of light that a lens can take in. Larger aperture sizes, which are numerically smaller, admit a greater amount of light and therefore generally allow better picture quality due to allowing lower ISO and faster shutter speed for a given exposure. But larger aperture lenses are larger and, more importantly, more expensive than smaller aperture lenses.
You will find yourself wanting wide-angle shots more than telephoto shots during a walk on the Great Wall. Consider a 35mm equivalent of a 28mm focal length the minimum. Wider is even better. Sometimes you must choose between a wider focal length and a larger aperture lens. In general, the wider focal length offers greater advantage. Great Wall photography is going to be outdoors and, in most cases, with good light, so a faster (larger aperture) lens is not as important as it is for indoor photography. Telephoto capability, unlike wide-angle capability, is not as important. Some modest telephoto, or zoom, capability, on the order of perhaps a 35mm equivalent of 135mm or so, can be useful, but much more than that is not worth the tradeoff of a smaller aperture.
Your choice of camera case is important. Make sure it's easy to access your camera. If you keep your camera in your backpack or some other inconvenient location, you will find yourself taking too few photos.
You'll want to make sure you have adequate storage because you will find yourself taking a lot of photos on the Great Wall. Make sure you have plenty of memory or film for your camera. You'll also want spare batteries, especially if you're going on a walk of more than one day.
In China, you'll need a battery charger that will work on 220 volts AC. You may also need a plug adapter for the power receptacles you will find in China. Two-prong plugs from the USA are compatible with most power receptacles in China. European and other type plugs may need an adapter.
You should bring a waterproof container for your camera in case you encounter rain. A suitably sized plastic bag with a zipper is adequate for this purpose.
Take the time to learn to use your camera and to test it at the same time and make sure it's going to be reliable. Time you spend getting to know your camera will pay off in making operation familiar to you and ensuring you are going to get good photos on the Great Wall of China.
If you're planning to use polarized sunglasses, make sure they are compatible with your camera equipment. Sometimes it's hard to see a screen with polarized glasses. Make sure you try holding your camera both horizontally and vertically when testing this.
You should carry an emergency medical kit on the Great Wall. Simple items like bandages and antibiotic cream are not always easy to find if you need them, so bring them along just in case. You may want to include blister treatment supplies in your medical kit.
A walk on the Great Wall is not like a walk in the woods. You are exposed to the sun nearly all of the time. Therefore, sun protection is especially important, and even more so for those that have sensitive skin.
Sun protection can be in the form of protective clothes and sunscreen. Protective clothes include a wide-brimmed hat and UV-rated sunglasses plus a shirt, preferably long-sleeved, and long pants. Modern sun-protection clothes are UPF-rated yet they are cool and breathable. Any uncovered skin should be protected by sunscreen.
It's nice to have a cell phone when you travel to China. You can make calls within China, and you can call your home country. A cell phone can be useful on the Great Wall, especially in case of emergency. You can bring a cell phone with you, or you can buy one in China. If you choose to bring your cell phone, you can buy or rent a compatible international GSM cell phone with international coverage, or you can buy a prepaid SIM card in China. You can purchase a plan with inexpensive international calling so you can stay in touch with home. While coverage is improving quickly, your cell phone is not guaranteed to work on the Great Wall, especially in remote areas.
You can dial 110 for the police in China. In the Beijing area, you can also call 6525-5486 for the Public Security Bureau's special foreigner's help line.
You may find it desirable to bring some restroom items with you.
The products you like may not be available in China, so if you aren't willing to substitute, be sure to bring enough with you. This includes items like toothpaste, deodorant, sunscreen, shaving cream, and so forth. Most of these items are not hard to get, although the specific brand or type may differ from what you normally use. Also, your favorite feminine hygiene items may well be unavailable in China, so bring a supply with you.
Don't expect to find toilet paper in public restrooms or in small hotels, guest houses, trains and buses in China. You should carry your own.
Of course, it's absolutely essential to bring with you any prescription medications that you will need during your trip. As mentioned in the safety equipment section, an emergency medical kit is essential and blister treatment supplies are worth considering.
You may or may not want to bring food and drink supplies with you to China. Again, anything special that you depend on may not be available in China, so ask yourself whether you will be able to find suitable substitutes or whether you should bring some consumables of your own.
It's important to remember that you must not drink tap or stream water in China. You must boil water or purify it in some other way, or buy bottled water or other drinks. It's easy to find bottled water in China. But be sure the bottled water you buy is legitimate, sealed product from a reputable source. And by the way, you will find very few streams indeed while walking the Great Wall.
Some of the types of food and drink supplies that you might want to consider bringing are a powdered electrolyte drink mix that can be mixed with water, dehydrated foods, energy bars or gels, trail mix, beef jerky, etc.
More and more people are discovering the benefits of a concept known as lightweight hiking or ultralight hiking. The idea is to significantly reduce the weight of your pack on hiking trips in order to maximize comfort and enjoyment. Lightweight hiking can be undertaken to various extents from minor to extreme weight reductions. Reducing the weight of your pack usually involves compromise. These compromises fall into the categories of doing without certain items and spending more money. But the pleasure of carrying a light load is hard to put a price on, and doing without certain items is often a very fair compromise in view of the reduced weight that is realized.
The longer your hike is, the more benefit you will realize from reducing your load. A light load is nice for one day, but as the length of your walk increases to several days, weeks, or months, the value of reduced weight becomes greater and greater, and the time and money you spend in developing a lightweight hiking solution pays off many times over.
To start with reducing your load, look at the main items that can contribute to weight in the first place. Traditionally, these are your tent, your sleeping bag, and your pack itself. The best way to reduce the weight of your tent is to forego it completely. The next best way is to spend a lot of money on a high-quality, lightweight tent, or to substitute a tarp or a bivouac sack. The same thing goes for a sleeping bag, but foregoing a sleeping bag is not as feasible for a long hike as foregoing a tent, so you may want to consider spending the money on a good, lightweight sleeping bag. One nice outcome of lightweight hiking is that, as your load becomes smaller and lighter, your backpack requirements also become smaller and lighter.
Once you've reduced the weight of these three primary items, go ahead and evaluate everything else you plan to bring. For each item, ask yourself these questions: Do I really need this item? If so, can I substitute something of lighter weight? Can I combine two or more items into one multi-purpose item? You might want to go through this process more than once. You may also want to make a list of each item you will carry and its weight. This can be helpful in identifying opportunities for weight reduction.
Resist bringing spares. About the only thing you need more than one of is a few clothing items and perhaps water containers. For everything else, just one will suffice.
Do not unduly compromise safety when reducing weight. You absolutely must carry enough water, and you must carry emergency and navigation equipment even if you don't think it's likely that you will need them.
Once you have finished, it's reasonable to expect a total weight of about 5 kilograms (11 pounds) not including food and water. You'll be thanking yourself when you're walking the Great Wall and you completely forget you even have a load on your back!
Testing your hiking and electronic equipment is a good idea, especially if you're planning a relatively long hike. Try to test your equipment in a similar way that you will use it in China. For example, use it all day long rather than just for a few hours, and use it in an environment that is similar to the environment you expect in China.
For example, if you plan to visit China during the winter, use your camera on a really cold day to see how long the battery lasts in low temperatures.
Usually, problems with equipment will show up relatively early, so testing is worthwhile. A failure during a test may be resolved as simply as purchasing spare batteries or returning a defective item to the store for a replacement, whereas if the failure occurs on the Great Wall, it can be a serious problem or a major disappointment.
Here are details on planning short, medium, and long hikes on the Great Wall.