There are critical backpack contents which must always be carried.
Every item in a pack should be evaluated to provide full function at the least weight and volume. Common sense should always prevail. The most important part of any backpack content is the emergency kit. The well-planned day begins with the expectation for enjoyment of a fully researched, magnificent experience that will occur but the hike begins with being prepared for the worst. Following is a list of items commonly kept in the emergency kit inside a large Ziplock freezer bag at the bottom of the backpack.
Emergency Kit Mirror
A small mirror is a signalling device. Acrylic is preferred over glass for safety. The mirror can capture the power of the sun and send an SOS signal in the event of an emergency. Planes overhead will radio the precise-location of potential distress signals to ground-based rescue services. Careful here. There are many documented cases of expensive rescue missions being launched erroneously. SOS in Morse Code is three short, three long, three short. More modern satellite communication services like SPOT and inReach offer more sophisticated GPS locator solutions. Keep the mirror in reserve.
The situation may require the capability to make a fire quickly and easily. Waterproof or storm proof matches are sealed inside a small, waterproof, cylindrical case. Carrying a volatile form of tinder like tiny, wax impregnated fire starter logs can expedite the process . There are many high-tech, expensive solutions for starting a fire. Simple, proven and practical seems wise.
Four articles of clothing are carried in the emergency kit. They are:
Pantyhose are a thin warm bottom layer which also doubles as a fairly decent, temporary fan belt for the car.
Tights are again a warm bottom layer. The extra layers can make a significant difference in comfort.
The remaining two pieces of clothing are upper and lower body, silk or merino wool, long underwear. They are all made of thin material which can be rolled up, stuffed into a smaller Ziplock freezer bag, and compacted to remove air before the bag is sealed. These fundamental pieces provide a lot of clothing in a tiny space. The contents can go a long ways towards surviving an unscheduled, cold, overnight stay.
Water Purification Tablets or Kit
It is best to err on the side of caution and assume all wilderness water is contaminated, no matter how good it looks. Some people are more susceptible to giardia bacteria (beaver fever) than others. The lagellated protozoan parasite can make some people very sick. Some people recover quickly but there are cases of very long-term recovery or some level of permanent affliction. Giardia should not be underestimated. A modern chemical water purification kit, is an emergency alternative to carrying more bulky water filtration systems. Prepare the water according to instruction. There are more expensive and advanced tablets and solutions worthy of review.
In recent years, many more practical water purification options have become available. Consult the Internet references.
This is additional to, and not a substitute for, an appropriate first aid kit. A small pill-box contains a few 200 mg ibuprofen tablets, an antihistamine for stings or allergic reactions, and more potent, prescription, codeine based pain killers. The tablets need to be renewed annually.
Green Garbage Bag
A large, sturdy, tightly folded, green garbage bag can be useful in a wide variety of shelter and moisture management applications.
First Aid Kit
A day hiking first aid kit is a small, fundamental and comprehensive resource which contains a variety of bandages, a disinfectant, some gauze and tape, etc. You can make up your own in a small zip lock bag or purchase an appropriate first aid kit and modify it as required. The kit may be unique to a specific area or activity.
An Emergency Blanket is a thin Mylar film of aluminized plastic. It has a dull side and a glossy side. The glossy side goes towards the body and reflects body heat inward as well as providing protection from wind and water. The blanket will help to keep a person warmer and more comfortable while someone goes for help. Alternatives include an emergency, heat-reflective blanket or compact bivy sack.
Like the mirror, the whistle is an important signalling device. In the wilderness, three short blasts will bring anyone within audible range to the rescue. You may think you are alone but it is likely the whistle will be heard. In the mountains, sound bounces. Although reflection extends the range of sound, it can confuse direction. Repeat three short blasts at regular intervals. When a response of any kind is heard, holler to guide potential assistance. Do not practice this in the wilderness.
A safely and carefully located, smoky fire can assist with location. When lost, find the nearest open area where discovery is possible, hunker down, and wait for help. Do not change location. Everything you need to stay comfortable is in the emergency kit and the most important thing done before leaving, was to tell someone the planned destination and the anticipated time of return. Modern satellite communication devices can alleviate help the situation. Cell phone coverage is becoming more prolific. Satellite communication is becoming a cost effective alternative.
An inexpensive, compact emergency rain poncho in the backpack supplements a small, collapsible umbrella and rain gear. Most of the time the umbrella will suffice.
eZeefit ankle sleeves/shims are a modern alternative to moleskin or blister packs.
Moleskin is an adhesive foot protection to prevent blisters. Moleskin does not like to stay where it belongs. Duct tape has been used.
These provide protection from sustained, high wind. Often, only one is required to counter prevailing wind direction and prevent a headache. It is important to avoid compromising hearing any more than necessary.
A compact source of light is essential when the mission starts or unexpectedly finishes in darkness. A dual-power, LED version for optimum use of battery power is a good choice. Remember spare batteries. A second light source is a good idea.
A versatile knife can come in the form of a Swiss Army Knife or any viable alternative. Consider weight, volume and functionality. Aim for a minimal, sensible selection of functions.
A small, tube or container is adequate. A spray can is convenient but bulky. Keep it in a zip-lock bag. This applies to anything that can spill or leak.
Hiking on snow, at high altitude on a sunny day will exposes skin to intense and damaging sunlight. Cover the skin or use a sunscreen. A broad-brimmed hat combined with high-quality sunglasses are important to protect the forehead, ears and eyes.
Serious eye protection is important at high elevation in direct sun for prolonged periods, particularly on snow. Snow blindness is an unpleasant experience which can be extremely compromising in wilderness terrain. Glasses must be UV filtered, polarized and provide side protection. They can be expensive.
A folded section of aluminum foil is light and can be very useful in a variety of ways.
Compass, GPS, Guide, Map
Take trail instructions and know how to use them. Copy the pages from the guide which are needed for the day instead of hauling the entire guide. At trail junctions, or for locating interesting features on your trip that might otherwise be missed or forgotten, a good topographical map of the area is important. When disoriented or lost, place the map on the ground to line up with distinguishing, landmark mountains, rivers or features to confirm location. Carrying and knowing how to use a compass is a powerful skill set. GPS is a good solution in a wide variety of situations and the map takes care of business when the GPS is useless.
In an upper, inside, zippered and easily accessible pocket of the backpack, carry a Ziplock bag containing toilet paper, tissue and a few sealed packages of a wet wipe and a small poop scoop. If nature calls, everything needed is handy. Carry out what is reasonable and, bury what is not. Proper wilderness toiletry etiquette can be reviewed in the excellent book 'How to Shit in the Woods'.
An extra boot laces in the pack can be a valuable resource. They use virtually no space and add negligible weight. If a boot lace breaks, the solution is available. Boot laces are a couple of short lengths of strong, thin rope which can be invaluable in a wide variety of circumstances.
Duct tape can be very handy and important for temporary boot or clothing repair etc. Multiple applications are limited only by the imagination. The spool is large and takes a lot of space. The inside of the spool can be used to store other stuff or an amount of duct tape can be rolled onto a smaller spool like one from an empty cash register spool. Keep it in a Ziploc bag to prevent sticky edges from interfering with other backpack contents.
Finish off with extra batteries, the sealed lunch container and water bottles.
The lunch container seals tight to prevent odor transmission. Pack the lunch container with heavy things in one end (drink box, trail mix etc.) and the light stuff (hearty, healthy sandwich) in the other end. Place the lunch container in the backpack with the light stuff pointing up so a tiny, dense sandwich can be avoided.
There is space in the pack for a can of nutritional beverage in a Ziploc bag over the top of the lunch container. The Ziploc bag is handy to carry the used receptacle home without messing up the backpack. The lunch container holds more food than needed to be used in an emergency.
The hiking jacket can be kept on the back of the pack to dry for later use when required.
The space remaining in the pack is for the days additional layers. If the mark is missed, the clothing kits in the vehicle allow last-minute adjustments at the trail-head.
Pack contents vertically against the back of the back and use compression straps to keep the pack as thin as possible vertically.
Carrying as little as possible, and as much as needed, is an inexact science. To be close will be fine. Just a few of the days optional needs may include hiking crampons for icy surfaces, gaiters to keep snow and mud out of your boots. A toque, gloves, and scarf are often welcome. The conditions for the day may be much different from forecast and the range of conditions can vary dramatically as altitude is gained. The mission can be aborted and attempted again at a more opportune time.
The core contents of any backpack can vary. Recommendations must be general and may not apply to everyone or every situation. Individual requirements, and the hiking area (very hot vs very cold; easy terrain vs very challenging terrain; the nature of the mission), will influence backpack content decisions.
Winter emergency backpack contents may differ from the summer kit.