6 Answers

plenty of water, a triangular bandage (this can be used for anything including a sling) stingose or the equivalent ,sunburn protection (sp 15 or better) a mobile phone, your watch, always let someone know where your going and an approximate time of your return

Depends where you are going, for instance, if you are going to the Tropics, insect repellent is essential.

Space blanket
Hat with wide brim
Flashlight or cyalume light sticks
Waterproof Matches and lighter
2 Quarts of water minimum
Without water, your whole body starts to suffer
Drink early and often, even in winter
Power Bar or other packaged, high-energy food source
Compass - know how to use it, even if you have a GPS
Camera - not really essential, but why not?
It's fun to look at the photos in the winter
Trail guide and maps
Cell phone
First aid kit - know how to use it
Duct tape or athletic tape
Benadryl - for bee stings and allergic reactions
Tell somebody where you are going and when you should be back - this could save your life 

http://www.thelionhearted.org/lifestyle/bills_hikes/emergency_items.htm 

Depends on where you are going and for how long....I always overpack and that can make for miserable traveling...........

Anything you want, as long as I'm not lugging it!

What to Pack for a Hike

Use these guidelines to determine what to pack for your hike. The first item on your list of things to carry is water, even if you're taking a short hike. It's all too easy to become dehydrated during a hike, especially in warm weather. So you'll need to drink plenty of water as you go, even if you don't feel particularly thirsty.

You can't count on finding drinkable water along your route, so you'll need to carry enough for your entire hike. If you're planning a short hike, you may be able to get away with one bottle of water. For longer hikes, try filling three or four containers so that you can distribute the weight evenly in your pack.

The next item on the list is food. Hiking takes a lot of energy -- at least 300 calories an hour (more if you're hiking at a brisk pace or on rugged or uphill terrain). Even if you eat an extra-large breakfast before you begin, you're likely to get hungry on the trail.

Because you'll probably have to carry all the food you'll need, try to choose foods that are nourishing yet low in weight and bulk -- and easy to prepare in advance. Particularly in hot weather, avoid bringing perishable foods, such as milk products and raw meat, that can spoil easily.

Sandwiches as well as snacks of nuts, dried fruits, and dry cereal are favorite choices. They'll provide you with the carbohydrates you need for energy. A variety of dehydrated foods are also available, but these require water to make them edible.

Another essential item is a small first aid kit. This kit should contain bandages or sterile pads and tape, antiseptic, and aspirin or another painkiller. In addition, you may want to carry a pocket knife or a small pair of scissors, matches, a small flashlight, biodegradable toilet paper, insect repellent, and a good sunscreen. You may also want to bring a compass along. If you have a map of the area, be sure to keep it handy.

To carry all these items, you'll need a pack. The type you choose depends on the length of the hikes you intend to take. If you plan on taking short hikes, a fanny pack or day pack should be large enough. If you go on overnight hikes, however, you'll need a backpack that's a little roomier.

Packs come in a variety of models, sizes, materials, and colors. Some have internal frames, others have external frames. To find a pack that's right for you, visit a sporting goods store or outdoor gear store that has knowledgeable salespeople. Discuss with them the type of hiking you'll be doing, the supplies you plan to carry, and the amount of money you're willing to spend.

Be sure, however, to try the pack on before you purchase it. You'll be the one carrying it around, so you'll want it to suit your body frame and feel comfortable. The pack should conform to your back. It should also have adjustable, padded shoulder straps and an adjustable waist belt that will allow you to distribute the weight of the pack to your hips as well as to your shoulders.

Once you've taken several day hikes, you may want to try an overnight hiking or backpacking trip. For these trips, you'll need to carry more supplies, including extra food and water, a sleeping bag, a powerful flashlight, a change of clothes, and perhaps even a tent and a small camping stove. This collection of necessities can add up to a heavy load.

Government researchers have found that carrying more than 25 pounds of weight for long periods can do more harm than good by straining the shoulders, back, and knees. This research grew out of complaints from soldiers who had to carry heavy packs during long marches. So it may be best to limit the load you carry on a hiking trip to 25 pounds, if it's at all possible.

To cut down on weight, try choosing nourishing foods that don't need to be cooked, so you won't have to carry cooking utensils. If you're purchasing a sleeping bag, tent, stove, or other equipment, choose lightweight models.

You know that a first-aid kit is an essential safety item to take along on your hike, but there are other ways to protect yourself from harm while hiking.