When you head out for a short hike on a beautiful day, it may be tempting to carry only a candy bar stuffed in your pocket and a water bottle in your hand. You might even bring the classic 10 essentials (see sidebar), with little concern about an unexpected night in the woods—or worse. But things can go wrong, leaving you on your own and lost. That's when a pocket survival kit can prove its worth.

You can put together your own kit that covers the four basic needs—shelter, warmth, signaling, and navigation—for about $200 to $300. Choosing top quality gear is imperative, because you may end up trusting your life to any one item.

"Focus on 'Hope for the best, prepare for the worst' in every outing," says Aaron Gorban, AMC's leadership training and risk management manager. "Never become complacent by believing 'It can't happen to me.'"

The following basic survival items are practical, functional, and able to fit in a pocket or belt pack. They can help you in any season, and should go with you every time you head out on the trail. You can think of them as a complement to the traditional 10 essentials.

Assembling a kit is just part of being prepared; you should acquire outdoor skills too. As Gorban says, "Gear is important, but also the knowledge to use that gear and have the ability to understand weather, the basics of first aid, and shelter."

The 10 Essentials The following items have been considered "essentials" for every hiker to carry since the The Mountaineers, a Seattle-based hiking and mountain climbing club, compiled the list in the 1930s. Map Compass Sunglasses and sunscreen Extra food and water Extra clothes Flashlight/headlamp First aid kit Fire starter Matches Knife

Shelter
In a survival situation, you could shelter under the low hanging branches of a conifer or the upturned roots of a large tree, or build a brush shelter. These are minimalist shelters; they give some protection, but you're not going to be very dry or warm if you encounter wet or cold weather. A thick bed of dry leaves or conifer branches provides insulation from the ground and allows you to conserve critical body heat.

Two pocket items that can make a big difference are a small tarp (about 8 feet by 8 feet) and an emergency bivouac ("bivy") sack. Tarps vary in resistance to tearing; choose one that will not easily rip. A tarp can actually make a fairly good emergency tent. To do this, angle a dead branch up against a standing tree and drape the tarp over it to form a tent. The single triangular opening by the tree should allow you enough room to enter and turn but not so much space that you lose body heat. By anchoring the tarp with rocks along the end and two sides, you can create a snug shelter. A tarp or plastic sheeting can also be used as a makeshift rain poncho or sun shelter.

An emergency bivy sack is a wind- and water-resistant emergency sleeping bag that rolls to a compact size. Some have a reflective lining that helps prevent heat loss. Lacking that, a Mylar blanket or two large plastic trash bags, one covering your lower body and one with an opening cut for your head and pulled over your upper body, would help retain heat and keep you dry.

Warmth
Leave No Trace guidelines, and regulations in some areas, discourage building fires in the backcountry. But if you are without a backpacking stove and in an emergency situation, fire can be essential. Fire, like shelter, provides both mental and physical comfort. The light drives the sometimes frightening darkness away and can signal others of your location, while the heat can dry wet clothing or boots and warm you. But fire is both hard to start and hard to put out. The first thought when building any fire is a safe location. Extremely dry conditions may cause fire to spread, or windy conditions can send embers onto your shelter. Always try to build an emergency fire in a cleared area near a water source.

Before you head out hiking, learn what tinder is available in your area. Birch and cedar bark, Spanish moss, pine cones, and many other region-specific items all work well. Tinder of these types will ignite easily and produce a quick, hot fire to start larger wood. You may also want to create "fuzz sticks" by making angled cuts with a knife along the length of small twigs, to make small chips stand out from the twig for easy ignition.

Fire can be started with matches, lighters, or spark tools, but a particularly practical starter is a refillable fluid lighter. These have no complicated mechanisms to operate and will stay lit without holding down a tiny valve (hard to do with cold, stiff fingers). They are also windproof, relatively water-resistant, and work at temperatures well below the standard butane lighters. Magnifiers, spark tools, magnesium bars, and other emergency means are useful secondary fire starters that you should become familiar with in all conditions. Always carry a secondary source in case of loss of your primary fire starter.

Attention signals
Methods to signal for help include a signal mirror, a flashlight, and a whistle. These three will guide help from the air or ground. The mirror is for daytime, long-distance signaling over many miles, the flashlight is for night signaling, and the whistle works both day and night and can pinpoint your location to nearby rescue personnel.

Using a rescue signal mirror requires good reflected sunlight and precise aiming. Don't wait to figure out how to use yours until those critical moments when you need to signal to search aircraft; practice the skills needed by signaling at home in a large field or other open area.

In choosing a flashlight, go with LED tactical lights, often used by professional police and fire department personnel. These lights cost more but have options like varying light output to save batteries and strobe features for signaling. They are usually only about 3 inches long for easy carry. NovaTac, SureFire, and Streamlight all produce such lights for police use, an indication of their ruggedness.

The whistle you carry should be one of the loudest you can buy. Commonly referred to as lifeboat or rescue models, they will carry farther than you can yell and last longer than your voice. Three blasts is the universal distress signal. When you decide to begin signaling by any of the three methods, remain in the same location until found.

Navigation
The debate over GPS or compass may never end. Nevertheless, any person who takes to the outdoors should understand how to navigate with a map and compass and carry both. Top-quality current topo maps are available from AMC and other sources. The U.S. Geological Survey maps are available widely, but many are lacking current trail data. Purchase waterproof maps or map holders, or store all maps in plastic bags.

Learn how to use your compass with any map. AMC offers courses and some compass makers, such as Brunton, have developed training DVDs for their products. Spend a few hours in training until you can find a point and navigate back to your starting point. Make sure you can plot a course, find your position on a map, and take a bearing. The baseplate compass (one without a sighting device or mirror) will generally help you to plot or find a position on maps but is difficult to use to get a bearing. You need a mirrored compass that has a marked baseplate and is adjustable for declination or magnetic north to get bearings and travel.

Use your compass's included lanyard (neck cord) or make your own using paracord or other soft nylon cord. The compass should always be firmly attached to you (and in your shirt pocket, if you have one), so it is less likely that you will sit on it or damage it if you fall.

At the beginning of any trip, do one final orientation to give yourself a general sense of the way the path, river, or mountain ridge runs in reference to where you started.

Other Important Gear
No one should head out without a good knife and a multitool. These both should be able to work hard while being comfortable and should be easily sharpened yet of tough enough steel to not wear easily.

The knife of choice is a fixed blade, 6 inches or less in overall length. The shorter models are easy to control. Fixed blades are generally stronger than folders and are convenient to retrieve with one hand from a sheath. Fixed blades are good for splitting firewood, whittling fire-starting "fuzz sticks," and other rough tasks such as rope cutting or digging.

The multitool is a tool kit for any on-trail repair. Most hikers find the screwdrivers, spring-loaded pliers, wire cutters, wood saw, and file the more useful of the tools. A top pick for survival situations is the type that opens one-handed and has a locking design so the tools will not fold closed under hard usage. Gerber and Leatherman are well made for survival. With the knife and multitool, you can smooth up shelter poles, cut cordage, shave tinder, remove splinters, and repair gear.

Putting It All Together
While no one plans to get into trouble when heading out on a hike, it's best to be ready just in case. Assembling a survival kit makes this easier. Store yours where it's handy to grab before you go, and be better prepared for the unexpected on your next adventure.