THE 10 ESSENTIALS are items every outdoor adventurer should include in his or her pack. The original list was devised in the 1930's by The Mountaineers, a Seattle-based hiking, climbing, and conservation organization, whose members get out in some truly dreadful weather—including in the rainy North Cascades, along the Olympic Peninsula, and on such snow-covered peaks as Mount Rainier.

The Mountaineers' essentials list was designed to keep climbers safe in case of accident, injury, or misadventure. Over time, like any classic, the list has been used and altered, but the core remains the same. Seventy years later, the list is included in many outdoor guides, including the latest edition of the Boy Scout Fieldbook.

Here's what you need—and why.

1. Pocketknife or multipurpose tool.

These enable you to cut strips of cloth into bandages, remove splinters, fix broken eyeglasses, and perform a host of repairs on malfunctioning gear—not to mention cut cheese and open cans.

2. First-aid kit.

Prepackaged first-aid kits for hikers are available at outfitters, but you can customize your kit with your favorite blister treatment and ointments for common outdoor ailments (a topical antihistamine, for example, to take care of itches and rashes). Double your effectiveness with knowledge: Take a 16-hour Wilderness First Aid Basics course from the Ameri-can Red Cross.
 

3. Extra clothing.

Above timberline, bring one more clothing layer than you think you'll need. Two rules: Avoid cotton (it dries slowly and keeps moisture close to your skin), and always carry a hat. A windproof, water-resistant fleece jacket can help you withstand ornery mountain conditions. Plastic baggies or extra socks can help keep hands warm.

4. Flashlight or headlamp with extra batteries.

Headlamps and flashlights allow you to find your way in the dark or signal for help. Headlamps are conve- nient for hands-free use.

5. Rain gear.

Remember that high mountains make their own weather, and storms can erupt suddenly and violently. Even in a temperate summer forest, a dousing rain can quickly chill you to the point of hypothermia. Rain gear protects against not only rain, but also wind, cold, and even insects.

6. Water bottle.

Without enough water, your body's muscles and organs simply can't perform as well. You'll be susceptible to hypothermia and altitude sickness, not to mention the abject misery of raging thirst. Al-xways carry plenty of water and stop often to drink.

7. Map and compass.

A map not only tells where you are and how far you have to go, it can help you find campsites, water, and an emergency exit route in case of an accident. A compass helps you find your way through unfamiliar terrain—especially in bad weather where you can't see the landmarks. A GPS (global positioning system) can also help—but it is no substitute for knowing how to read a map.

8. Matches and fire starter.

The warmth of a fire and a hot drink can help prevent hypothermia. Also, a fire can be a signal for help if you get lost. Carry matches and a small amount of fire starter protected in zipper-locking bags. Dripping candle wax on match tips helps waterproof them. Commercially available windproof and waterproof matches are also a good choice.

Fire starter is anything flammable, from pocket lint to filled-in journal pages. Pine needles and birch bark make especially good starter, even when wet.

9. Sun protection and sunglasses.

Especially above timberline, when there is a skin-scorching combination of sun and snow, you'll need sun-glasses to prevent snow blindness and sunscreen to prevent sunburn. Buy sunglasses that are ultraviolet ray (UV) resis-tant and have side flaps (ventilating holes that keep them from fogging).

Don't use sunscreen that's been sitting in your medicine cabinet for a season or more: It has probably lost at least some of the effectiveness of its sun-protection factor (SPF), a rating of how well and how long the sunscreen will keep you from getting sunburned. A light-colored hat with a wide brim is also an effective sun deterrent. In desert conditions, consider using a long-sleeved light shirt and lightweight loose-fitting long pants. Zipper-off legs give more versatility.

10. Trail food.

Nothing boosts energy and spirits as much as a quick trail snack. You can make your own trail mix with nuts, raisins, banana chips, and chocolate bits. The combination of sugar, fats, and potassium tastes great and provides quick energy, long-lasting calories, and replacement electrolytes.

Always take a bit more food than you think you will need. A lot of things could keep you out longer than expected, like a lengthy detour, get-ting lost, an injury, or difficult terrain.