What you take will depend on where you are going and how long you plan to be away, but any backpack should include the following:

• Candle and matches
• Cell phone
• Clothing (always bring something warm, extra socks and rain gear)
• Compass
• First aid kit
• Food (bring extra)
• Flashlight
• Foil (to use as a cup or signaling device)
• Hat
• Insect repellent
• Map
• Nylon filament
• Pocket knife
• Pocket mirror (to use as a signaling device)
• Prescription glasses (an extra pair)
• Prescription medications for ongoing medical conditions
• Radio with batteries
• Space blanket or a piece of plastic (to use for warmth or shelter)
• Sunglasses
• Sunscreen
• Trash bag (makes an adequate poncho)
• Water
• Waterproof matches or matches in a waterproof tin
• Water purification tablets
• Whistle (to scare off animals or to use as a signaling device)

Always allow for bad weather and for the possibility that you may be forced to spend a night outdoors unexpectedly.

It's a good idea to assemble a separate "survival pack" for each hiker to have at all times. In a small waterproof container, place a pocket knife, compass, whistle, space blanket, nylon filament, water purification tablets, matches and candle. With these items, the chances of being able to survive in the wild are greatly improved.