Any outdoor activity entails many risk

Risk

Risk is the potential that a chosen action or activity will lead to a loss . The notion implies that a choice having an influence on the outcome exists . Potential losses themselves may also be called "risks"...

s, even if participants do not recklessly place themselves in harm's way. Even a simple accident may create a dangerous situation that requires survival skills

Survival skills

Survival skills are techniques a person may use in a dangerous situation to save themselves or others...

. However, with the correct precautions, outdoor recreation can be enjoyable and safe.

General safety measures

Every hazard has its own safety measure, and every ailment a particular remedy. A standard precaution for all backcountry activities is carrying the "ten essentials

Ten Essentials

The "Ten Essentials" are survival items that hiking organizations recommend for safe travel in the backcountry.The Ten Essentials were first described in the 1930s by The Mountaineers, a hiking and mountain climbing club. Many regional organizations and authors recommend that hikers, backpackers,...

", a collection of tools chosen for their utility in preventing or reacting to various emergencies.

The common practice of traveling in a group improves safety in all regards. If one person is injured, group members can administer first aid

First aid

First aid is the provision of initial care for an illness or injury. It is usually performed by non-expert, but trained personnel to a sick or injured person until definitive medical treatment can be accessed. Certain self-limiting illnesses or minor injuries may not require further medical care...

 or seek help. A group can avoid poor decisions that a lone traveler might make. If an emergency occurs, a group can pool its muscle power, brain power, and body heat.

Another precaution is informing people outside of the hiking group of the itinerary and expected return time. (Expected hiking time can be estimated using Naismith's Rule

Naismith's Rule

Naismith's Rule is a rule of thumb that helps in the planning of a walking or hiking expedition by calculating how long it will take to walk the route, including ascents. The rule was devised by William W. Naismith, a Scottish mountaineer, in 1892...

.) A communication

Communication

Communication is the activity of conveying meaningful information. Communication requires a sender, a message, and an intended recipient, although the receiver need not be present or aware of the sender's intent to communicate at the time of communication; thus communication can occur across vast...

 device, such as a cell phone or a satellite phone

Satellite phone

A satellite telephone, satellite phone, or satphone is a type of mobile phone that connects to orbiting satellites instead of terrestrial cell sites...

, may help in the case of an emergency. However, with the exception of mountain tops that are in line-of-sight to populated areas, cell phone coverage in wilderness areas is often quite poor. In the wilderness one should always be prepared to hike out for help, if necessary.

Dangerous circumstances

Adventurers rarely get themselves hurt if they manage to avoid particularly dangerous situations.

Losing the way

Travelers may become lost either if a party cannot find its way, or if a traveler becomes separated from the party and cannot find it again. Lost hikers who cannot find their way to their destination on time may run out of food and water, or experience a change in weather, exacerbating the risk of hiking hazards. It's even easier to lose the way if trails do not exist.

If a group splits up into several subgroups moving at different speeds, one of the subgroups may take a wrong turn at a trail junction. A common custom to avoid this is for the leaders to stop at junctions and wait for the others. Keeping the group together is important in the wilderness, especially when visibility is blocked due to weather, rocks, or trees.

Carrying a map

Map

A map is a visual representation of an area—a symbolic depiction highlighting relationships between elements of that space such as objects, regions, and themes....

 and compass

Compass

A compass is a navigational instrument that shows directions in a frame of reference that is stationary relative to the surface of the earth. The frame of reference defines the four cardinal directions – north, south, east, and west. Intermediate directions are also defined...

 and knowing how to use them will decrease the risk of getting lost. Likewise, a Global Positioning System

Global Positioning System

The Global Positioning System is a space-based global navigation satellite system that provides location and time information in all weather, anywhere on or near the Earth, where there is an unobstructed line of sight to four or more GPS satellites...

 may prove invaluable, as it can pinpoint a traveler's location, revealing his exact position on the globe and the direction to roads, services and cities. Most GPS devices can also be designed to mark their path on a map, making it easy to backtrack. Family Radio Service

Family Radio Service

The Family Radio Service is an improved walkie talkie radio system authorized in the United States since 1996. This personal radio service uses channelized frequencies in the ultra high frequency band. It does not suffer the interference effects found on citizens' band at 27 MHz, or the...

, General Mobile Radio Service

General Mobile Radio Service

The General Mobile Radio Service is a licensed land-mobile FM UHF radio service in the United States available for short-distance two-way communication. It is intended for use by an adult individual who possesses a valid GMRS license, as well as his or her immediate family members...

, and amateur radio

Amateur radio

Amateur radio is the use of designated radio frequency spectrum for purposes of private recreation, non-commercial exchange of messages, wireless experimentation, self-training, and emergency communication...

s operating on the "2 meters

2 meters

The 2-meter amateur radio band is a portion of the VHF radio spectrum, comprising frequencies stretching from 144.000 MHz to 148.000 MHz in International Telecommunication Union region Regions 2 and 3 and from 144.000 MHz to 146.000 MHz in ITU Region 1...

" band may help maintain communication. Whistles, signal mirrors, and flashing lights are low-tech emergency signals.

Without a distant focal point such as a mountain top, or the sun or moon, people who are lost tend to wander in circles.

Inclement weather

Blizzard

Blizzard

A blizzard is a severe snowstorm characterized by strong winds. By definition, the difference between blizzard and a snowstorm is the strength of the wind. To be a blizzard, a snow storm must have winds in excess of with blowing or drifting snow which reduces visibility to 400 meters or ¼ mile or...

s, flash flood

Flash flood

A flash flood is a rapid flooding of geomorphic low-lying areas—washes, rivers, dry lakes and basins. It may be caused by heavy rain associated with a storm, hurricane, or tropical storm or meltwater from ice or snow flowing over ice sheets or snowfields...

s, fog

Fog

Fog is a collection of water droplets or ice crystals suspended in the air at or near the Earth's surface. While fog is a type of stratus cloud, the term "fog" is typically distinguished from the more generic term "cloud" in that fog is low-lying, and the moisture in the fog is often generated...

, sandstorm

Dust storm

A dust / sand storm is a meteorological phenomenon common in arid and semi-arid regions. Dust storms arise when a gust front or other strong wind blows loose sand and dirt from a dry surface. Particles are transported by saltation and suspension, causing soil to move from one place and deposition...

, tornado

Tornado

A tornado is a violent, dangerous, rotating column of air that is in contact with both the surface of the earth and a cumulonimbus cloud or, in rare cases, the base of a cumulus cloud. They are often referred to as a twister or a cyclone, although the word cyclone is used in meteorology in a wider...

s, and other meteorological events may or may not be predictable, and may require immediate response for survival. Some may restrict visibility, as does night

Night

Night or nighttime is the period of time when the sun is below the horizon. This occurs after dusk. The opposite of night is day...

fall, which may prevent further travel. Gusts of wind

Wind

Wind is the flow of gases on a large scale. On Earth, wind consists of the bulk movement of air. In outer space, solar wind is the movement of gases or charged particles from the sun through space, while planetary wind is the outgassing of light chemical elements from a planet's atmosphere into space...

 may physically knock a hiker or climber off a ledge or narrow trail. Lightning

Lightning

Lightning is an atmospheric electrostatic discharge accompanied by thunder, which typically occurs during thunderstorms, and sometimes during volcanic eruptions or dust storms...

 is a regular and serious threat in many regions.

Hazardous terrain

Backcountry avalanche

Avalanche

An avalanche is a sudden rapid flow of snow down a slope, occurring when either natural triggers or human activity causes a critical escalating transition from the slow equilibrium evolution of the snow pack. Typically occurring in mountainous terrain, an avalanche can mix air and water with the...

s are generally triggered by the immediate action of the party. Precautions include training, monitoring weather conditions to learn the history of the snow pack, digging hasty pits, modifying the route, passing one-by-one through dangerous areas, wearing avalanche beacons, and carrying avalanche probes and snow shovels. Other non-avalanche snow immersions can be similarly dangerous including tree well

Tree well

A tree well is a dangerous void or area of loose snow around the trunk of a tree which is surrounded by deep snow. A person, especially a skier or snowboarder, can easily fall into this well, possibly causing serious injury or death.-Formation:...

s and care should be taken in wooded backcountry areas following heavy snowfalls.

Other mass movements include icefall

Icefall

An icefall is a portion of some glaciers characterized by rapid flow and a chaotic crevassed surface. Perhaps the most conspicuous consequence of glacier flow, icefalls occur where the glacier bed steepens and/or narrows...

s, landslide

Landslide

A landslide or landslip is a geological phenomenon which includes a wide range of ground movement, such as rockfalls, deep failure of slopes and shallow debris flows, which can occur in offshore, coastal and onshore environments...

s, and rockfall

Rockfall

Rockfall or rock-fall refers to quantities of rock falling freely from a cliff face. A rockfall is a fragment of rock detached by sliding, toppling, or falling, that falls along a vertical or sub-vertical cliff, proceeds down slope by bouncing and flying along ballistic trajectories or by rolling...

. When choosing a campsite care must be taken to avoid those along with snags, dead trees, trees with large dead branches, or trees that have previously been through a forest fire. Collectively, these are called "widowmakers" by experienced campers.

• Slips may occur on:
  • Wet rocks or logs. Walking in streams, rivers, lakes, and other water is dangerous due to poor visibility, uneven surfaces, smooth and algae
    Algae
    Algae are a large and diverse group of simple, typically autotrophic organisms, ranging from unicellular to multicellular forms, such as the giant kelps that grow to 65 meters in length. They are photosynthetic like plants, and "simple" because their tissues are not organized into the many...
    
     or moss
    Moss
    Mosses are small, soft plants that are typically 1–10 cm tall, though some species are much larger. They commonly grow close together in clumps or mats in damp or shady locations. They do not have flowers or seeds, and their simple leaves cover the thin wiry stems...
    
    -covered rocks, and the current of the stream. The tops of waterfalls are especially dangerous because of fast moving water and smooth, slanted rocks. Rubber soles grip poorly on slime, compared to felt soles, crampons, or hob-nailed boots. Precautions include awareness of the danger, using hiking sticks, loosening packs straps to lower gravity and in case of being submerged, and crossing with other people linked arm to arm.
  • Loose material. Loose gravel or scree on top of smooth rock acts like ball bearing
    Ball bearing
    A ball bearing is a type of rolling-element bearing that uses balls to maintain the separation between the bearing races.The purpose of a ball bearing is to reduce rotational friction and support radial and axial loads. It achieves this by using at least two races to contain the balls and transmit...
    
    s. Precautions include spotting the situation ahead, keeping knees bent and weight forward, using hiking sticks, and brushing aside the gravel where possible.
  • Ice
    Ice
    Ice is water frozen into the solid state. Usually ice is the phase known as ice Ih, which is the most abundant of the varying solid phases on the Earth's surface. It can appear transparent or opaque bluish-white color, depending on the presence of impurities or air inclusions...
    
    

• Drowning
  Drowning
  Drowning is death from asphyxia due to suffocation caused by water entering the lungs and preventing the absorption of oxygen leading to cerebral hypoxia....
  
  s are especially likely when accompanied by head injuries, in very cold water, or in white water. Head injuries may render people unconscious. Cold water can sap energy quickly. White water may be so frothy that it is impossible to float, or even swim, to the surface.

Pre-existing medical conditions

Some medical pre-existing condition

Pre-existing condition

A pre-existing condition is a risk with extant causes that is not readily compensated by standard, affordable insurance premiums. Pre-existing condition exclusions by the insurance industry are meant to cope with adverse selection by potential customers. Such exclusions have become a topic in the...

s may be triggered or worsened by outdoor activity, particularly when it is sudden or strenuous. Examples include heart disease

Heart disease

Heart disease, cardiac disease or cardiopathy is an umbrella term for a variety of diseases affecting the heart. , it is the leading cause of death in the United States, England, Canada and Wales, accounting for 25.4% of the total deaths in the United States.-Types:-Coronary heart disease:Coronary...

, asthma

Asthma

Asthma is the common chronic inflammatory disease of the airways characterized by variable and recurring symptoms, reversible airflow obstruction, and bronchospasm. Symptoms include wheezing, coughing, chest tightness, and shortness of breath...

, diabetes, anemia

Anemia

Anemia is a decrease in number of red blood cells or less than the normal quantity of hemoglobin in the blood. However, it can include decreased oxygen-binding ability of each hemoglobin molecule due to deformity or lack in numerical development as in some other types of hemoglobin...

, and allergies

Allergy

An Allergy is a hypersensitivity disorder of the immune system. Allergic reactions occur when a person's immune system reacts to normally harmless substances in the environment. A substance that causes a reaction is called an allergen. These reactions are acquired, predictable, and rapid...

. Vertigo

Vertigo (medical)

Vertigo is a type of dizziness, where there is a feeling of motion when one is stationary. The symptoms are due to a dysfunction of the vestibular system in the inner ear...

 and neurological illnesses may have serious consequences on dangerous terrain.

Metabolic imbalances

Metabolic imbalances can affect general functioning and lead to other injuries.

• Dehydration
  Dehydration
  In physiology and medicine, dehydration is defined as the excessive loss of body fluid. It is literally the removal of water from an object; however, in physiological terms, it entails a deficiency of fluid within an organism...
  
  can rapidly incapacitate an adventurer, especially in warm weather. In conditions of low humidity, sweat evaporates so quickly that a person may not notice the water loss. Carrying and drinking an adequate amount of water helps avoid dehydration. Depending on conditions, two liters of water may be enough for a day hike, but under hot conditions (such as hiking the Grand Canyon
  Grand Canyon
  The Grand Canyon is a steep-sided canyon carved by the Colorado River in the United States in the state of Arizona. It is largely contained within the Grand Canyon National Park, the 15th national park in the United States...
  
   in summer), one liter per hour may be required. Naturally occurring water is often unfit to drink (see Potability of backcountry water
  Potability of backcountry water
  Wilderness acquired diarrhea , wilderness-acquired diarrhea, wilderness diarrhea, or backcountry diarrhea, is diarrhea that is caused by pathogens that have infected people when they were in the wilderness. It is a much-discussed hazard among backpackers, hikers, campers and other outdoor...
  
  ).
• Sweating removes not only water, but also salt. This may result in a deficiency of sodium
  Sodium
  Sodium is a chemical element with the symbol Na and atomic number 11. It is a soft, silvery-white, highly reactive metal and is a member of the alkali metals; its only stable isotope is 23Na. It is an abundant element that exists in numerous minerals, most commonly as sodium chloride...
  
   (hyponatremia
  Hyponatremia
  Hyponatremia is an electrolyte disturbance in which the sodium concentration in the serum is lower than normal. In the vast majority of cases, hyponatremia occurs as a result of excess body water diluting the serum sodium and is not due to sodium deficiency. Sodium is the dominant extracellular...
  
  ). Eating salty snacks together with drinking water helps to avoid this problem.
• If deprived of food for several days, travelers may become malnourished
  Malnutrition
  Malnutrition is the condition that results from taking an unbalanced diet in which certain nutrients are lacking, in excess , or in the wrong proportions....
  
  . Malnutrition takes several weeks to kill a person, but because it impairs judgment, it can cause problems much sooner. Low blood sugar may have a similar effect, especially for those with diabetes. Carrying extra food will minimize risk to the hiker.
• Hypothermia
  Hypothermia
  Hypothermia is a condition in which core temperature drops below the required temperature for normal metabolism and body functions which is defined as . Body temperature is usually maintained near a constant level of through biologic homeostasis or thermoregulation...
  
  is a potentially fatal drop in core body temperature. It occurs most easily in cold weather and when wet. Wet or damp clothing (due to rain, sweat, stream crossings, etc.) can bring it on even in relatively warm air, particularly at high elevation, windy conditions, or at low humidity. Even if hypothermia does not kill the victim directly it causes confusion, irrationality and impaired judgment, increasing the risk of other injuries. Sufficient clothing helps prevent hypothermia, but some materials (especially cotton
  Cotton
  Cotton is a soft, fluffy staple fiber that grows in a boll, or protective capsule, around the seeds of cotton plants of the genus Gossypium. The fiber is almost pure cellulose. The botanical purpose of cotton fiber is to aid in seed dispersal....
  
  ) are discouraged for their ability to absorb and hold water.
• Heat exhaustion, possibly developing into heatstroke, can occur in hot weather, particularly if one is dehydrated or dressed too warmly. The risk of heatstroke can be minimized by avoiding direct sun if the temperature is too high, and staying wet when possible. This is a life-threatening condition: a victim must be cooled off and transported to a hospital immediately.
• Altitude sickness
  Altitude sickness
  Altitude sickness—also known as acute mountain sickness , altitude illness, hypobaropathy, or soroche—is a pathological effect of high altitude on humans, caused by acute exposure to low partial pressure of oxygen at high altitude...
  
  results from climbing rapidly to elevations beyond 2,500 metres (approximately 8,000 feet). The process of acclimatization generally takes several days, but may be helped by drugs, such as Diamox. Acute mountain sickness or AMS may develop into high altitude pulmonary edema
  Pulmonary edema
  Pulmonary edema , or oedema , is fluid accumulation in the air spaces and parenchyma of the lungs. It leads to impaired gas exchange and may cause respiratory failure...
  
   (HAPE) or high altitude cerebral edema
  High altitude cerebral edema
  High altitude cerebral edema is a severe form of altitude sickness. HACE is the result of swelling of brain tissue from fluid leakage and almost always begins as acute mountain sickness...
  
   (HACE), both of which are life threatening and require immediate transportation to a lower altitude.
• Carbon monoxide poisoning
  Carbon monoxide poisoning
  Carbon monoxide poisoning occurs after enough inhalation of carbon monoxide . Carbon monoxide is a toxic gas, but, being colorless, odorless, tasteless, and initially non-irritating, it is very difficult for people to detect...
  
  may occur in tents, igloos, cabins, or trailers due to faulty or misused equipment. It may also occur near the exhausts of motorboats, where the CO concentrations can be high enough to be quickly fatal.

Topical injuries

• Frostbite
  Frostbite
  Frostbite is the medical condition where localized damage is caused to skin and other tissues due to extreme cold. Frostbite is most likely to happen in body parts farthest from the heart and those with large exposed areas...
  
  can occur when bare skin is exposed to very low temperatures. For very cold weather, clothing can be arranged to minimize the amount of exposed skin. Maintaining good circulation is very important. Frostbitten tissue should not be re-warmed in the field.
• Sunburn
  Sunburn
  A sunburn is a burn to living tissue, such as skin, which is produced by overexposure to ultraviolet radiation, commonly from the sun's rays. Usual mild symptoms in humans and other animals include red or reddish skin that is hot to the touch, general fatigue, and mild dizziness. An excess of UV...
  
  , which may occur in hot or cold conditions, can be debilitating. In snowy conditions special care must be taken to protect areas affected by reflected sunlight. In hot conditions, all skin should be covered from direct sunlight. Some areas, like the back of the knees, back of the neck, back of the ears, and bottom of the nose, are often neglected when sunscreen is applied.
• Snow blindness
  Snow blindness
  Photokeratitis or ultraviolet keratitis is a painful eye condition caused by exposure of insufficiently protected eyes to the ultraviolet rays from either natural or artificial sources. Photokeratitis is akin to a sunburn of the cornea and conjunctiva, and is not usually noticed until several...
  
  , a burning of the cornea
  Cornea
  The cornea is the transparent front part of the eye that covers the iris, pupil, and anterior chamber. Together with the lens, the cornea refracts light, with the cornea accounting for approximately two-thirds of the eye's total optical power. In humans, the refractive power of the cornea is...
  
  , is caused by the intense ultraviolet solar radiation multiplied by sunlit snow.
• Burn
  Burn (injury)
  A burn is a type of injury to flesh caused by heat, electricity, chemicals, light, radiation or friction. Most burns affect only the skin . Rarely, deeper tissues, such as muscle, bone, and blood vessels can also be injured...
  
  s occur when dealing with camp stoves. Boiling pots are overturned, clogged fuel lines explode, hot metal is touched with bare skin. Burns are also caused by campfire
  Campfire
  A campfire is a fire lit at a campsite, to serve the following functions: light, warmth, a beacon, a bug and/or apex predator deterrent, to cook, and for a psychological sense of security. In established campgrounds they are usually in a fire ring for safety. Campfires are a popular feature of...
  
  s, cookfires and bonfire
  Bonfire
  A bonfire is a controlled outdoor fire used for informal disposal of burnable waste material or as part of a celebration. Celebratory bonfires are typically designed to burn quickly and may be very large...
  
  s.
• Lacerations may be caused by careless use of knives, axes, or contact with sharp rocks or barbed wire. Tetanus
  Tetanus
  Tetanus is a medical condition characterized by a prolonged contraction of skeletal muscle fibers. The primary symptoms are caused by tetanospasmin, a neurotoxin produced by the Gram-positive, rod-shaped, obligate anaerobic bacterium Clostridium tetani...
  
   and other infections can result.
• Poisonous plants, such as poison ivy
  Poison ivy
  Toxicodendron radicans, better known as poison ivy , is a poisonous North American plant that is well known for its production of urushiol, a clear liquid compound found within the sap of the plant that causes an itching rash in most people who touch it...
  
   or stinging nettle
  Stinging nettle
  Stinging nettle or common nettle, Urtica dioica, is a herbaceous perennial flowering plant, native to Europe, Asia, northern Africa, and North America, and is the best-known member of the nettle genus Urtica...
  
   (see list), cause rash
  Rash
  A rash is a change of the skin which affects its color, appearance or texture. A rash may be localized in one part of the body, or affect all the skin. Rashes may cause the skin to change color, itch, become warm, bumpy, chapped, dry, cracked or blistered, swell and may be painful. The causes, and...
  
  es.
• Plant thorns and animal quills can cause deep puncture wound
  Wound
  A wound is a type of injury in which skin is torn, cut or punctured , or where blunt force trauma causes a contusion . In pathology, it specifically refers to a sharp injury which damages the dermis of the skin.-Open:...
  
  s, and can be difficult to remove, often requiring pliers.

Animals

In many areas, adventurers may encounter large predatory animal

Animal

Animals are a major group of multicellular, eukaryotic organisms of the kingdom Animalia or Metazoa. Their body plan eventually becomes fixed as they develop, although some undergo a process of metamorphosis later on in their life. Most animals are motile, meaning they can move spontaneously and...

s such as bear

Bear

Bears are mammals of the family Ursidae. Bears are classified as caniforms, or doglike carnivorans, with the pinnipeds being their closest living relatives. Although there are only eight living species of bear, they are widespread, appearing in a wide variety of habitats throughout the Northern...

s, or cougars. These animals rarely seek out humans as food, but they will attack under some conditions. Some hazardous encounters occur when animals raid human property for food. Additionally, if travelers come upon an unsuspecting animal and surprise it, it may attack. Regularly making loud noise, such as by clapping or yelling, reduces the risk of surprising an animal. Some people use bear bells as noisemakers, but these are usually too quiet to be heard from far away. Any mammal infected with rabies

Rabies

Rabies is a viral disease that causes acute encephalitis in warm-blooded animals. It is zoonotic , most commonly by a bite from an infected animal. For a human, rabies is almost invariably fatal if post-exposure prophylaxis is not administered prior to the onset of severe symptoms...

 may behave unexpectedly, even aggressively, and could infect a human with rabies by biting.

Venomous animals, including snake

Snake

Snakes are elongate, legless, carnivorous reptiles of the suborder Serpentes that can be distinguished from legless lizards by their lack of eyelids and external ears. Like all squamates, snakes are ectothermic, amniote vertebrates covered in overlapping scales...

s, scorpion

Scorpion

Scorpions are predatory arthropod animals of the order Scorpiones within the class Arachnida. They have eight legs and are easily recognized by the pair of grasping claws and the narrow, segmented tail, often carried in a characteristic forward curve over the back, ending with a venomous stinger...

s, spider

Spider

Spiders are air-breathing arthropods that have eight legs, and chelicerae with fangs that inject venom. They are the largest order of arachnids and rank seventh in total species diversity among all other groups of organisms...

s and bee

Bee

Bees are flying insects closely related to wasps and ants, and are known for their role in pollination and for producing honey and beeswax. Bees are a monophyletic lineage within the superfamily Apoidea, presently classified by the unranked taxon name Anthophila...

s, may cause harm either directly or through anaphylactic shock. Overall, the greatest danger is from insects, such as mosquito

Mosquito

Mosquitoes are members of a family of nematocerid flies: the Culicidae . The word Mosquito is from the Spanish and Portuguese for little fly...

es, tick

Tick

Ticks are small arachnids in the order Ixodida, along with mites, constitute the subclass Acarina. Ticks are ectoparasites , living by hematophagy on the blood of mammals, birds, and sometimes reptiles and amphibians...

s and flea

Flea

Flea is the common name for insects of the order Siphonaptera which are wingless insects with mouthparts adapted for piercing skin and sucking blood...

s, which carry communicable diseases.

Internal injuries

When combined with lack of proper physical conditioning, cumbersome backpack

Backpack

A backpack is, in its simplest form, a cloth sack carried on one's back and secured with two straps that go over the shoulders, but there can be exceptions...

s increase the risk of missteps and falls, particularly on difficult terrain. Poor judgment due to exhaustion or inattention on steep or slippery slopes can also lead to injury.

• Ankle
  Ankle
  The ankle joint is formed where the foot and the leg meet. The ankle, or talocrural joint, is a synovial hinge joint that connects the distal ends of the tibia and fibula in the lower limb with the proximal end of the talus bone in the foot...
  
   sprain
  Sprain
  A sprain is an injury in a joint, caused by the ligament being stretched beyond its capacity. A muscular tear caused in the same manner is referred to as a strain. In cases where either ligament or muscle tissue is torn, immobilization and surgical repair may be necessary...
  
  is a common and debilitating injury. Proper hiking boot
  Hiking boot
  Hiking boots are footwear specifically designed for the sport of hiking. They are considered the most important hiking gear since their quality and durability can determine a hiker's ability to move farther, faster, and more safely...
  
  s can help prevent it.
• Foot blister
  Blister
  A blister is a small pocket of fluid within the upper layers of the skin, typically caused by forceful rubbing , burning, freezing, chemical exposure or infection. Most blisters are filled with a clear fluid called serum or plasma...
  
  s are caused by friction and irritation of the skin. Wet socks and poorly-fitting shoes precipitate the occurrence of blisters. Two layers of socks (using liner socks) help prevent blisters, and moleskin
  Moleskin
  Moleskin, originally referring to the short, silky fur of a mole, is heavy cotton fabric, woven and then sheared to create a short soft pile on one side. The word is also used for clothing made from this fabric, as well as adhesive pads stuck to the skin to prevent blisters.Clothing made from...
  
   can be applied to blister-prone areas as a treatment or preventive measure.
• Back injury
  Back injury
  Back injuries result from damage, wear, or trauma to the bones, muscles, or other tissues of the back. Common back injuries include sprains and strains, herniated disks, and fractured vertebrae. The lumbar is often the site of back pain. The area is susceptible because of its flexibility and the...
  
  may result from packing more than one can carry or not having a proper backpack. A pack for backpacking
  Backpacking (wilderness)
  Backpacking combines the activities of hiking and camping for an overnight stay in backcountry wilderness...
  
   should be bought from a recreational store, and as a rule of thumb, a person who is not overweight can comfortably carry up to one third of his or her body weight, however a backpack weighing more than 50 pounds should be avoided. Hiking poles may also reduce the likelihood of back injuries by spreading the load across multiple points. Care should be taken to lift and put on the pack with the least strain.

Digestive infections

Surface water in the wilderness can contain viruses, bacteria or parasites. The latter two can cause dysentery

Dysentery

Dysentery is an inflammatory disorder of the intestine, especially of the colon, that results in severe diarrhea containing mucus and/or blood in the faeces with fever and abdominal pain. If left untreated, dysentery can be fatal.There are differences between dysentery and normal bloody diarrhoea...

 or wilderness diarrhea in untreated water and can be spread person-to-person by poor hygiene in camp. The most common cause of wilderness diarrhea is the parasite Giardia

Giardia

Giardia is a genus of anaerobic flagellated protozoan parasites of the phylum Metamonada in the supergroup "Excavata" that colonise and reproduce in the small intestines of several vertebrates, causing giardiasis, commonly known as Beaver fever...

.

External links

• A report of carbon monoxide poisoning from a motorboat (U.S. Centers for Disease Control and Prevention)
• Outdoor & adventure education injury/fatality rates & comparative statistics