Hazards of outdoor recreation

Outdoor recreation, such as hiking, camping, canoeing, cycling, or skiing, entails risks, even if participants do not recklessly place themselves in harm's way. In some circumstances, such as being in remote locations or in extreme weather conditions, even a minor accident may create a dangerous situation that requires survival skills. However, with correct precautions, even fairly adventurous outdoor recreation can be enjoyable and safe.
Every hazard has its own safety measure, and every ailment a particular remedy. A standard precaution for all back country activities is carrying the "ten essentials", 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 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 group of the itinerary and expected return time (expected hiking time can be estimated using Naismith's rule). A communication device, such as a cell phone or a satellite phone, 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.
Blizzards, flash floods, fog, dust or sandstorms, tornadoes, and other meteorological events may or may not be predictable, and may require immediate response for survival. Lightning is a frequent and serious threat in many regions.
Backcountry avalanches 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 wells.
Other mass movements include icefalls, landslides, and rockfalls. When choosing a campsite care must be taken to avoid those along with dead trees, snags, 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:
When travelling over glaciers, crevasses pose a grave danger. These giant cracks in the ice are not always visible, as snow can be blown and freeze over the top to make a snowbridge. At times snowbridges can be as thin as a few inches. Climbers and hikers use ropes to protect themselves from such hazards. Basic gear for glacier travel includes crampons and ice axes, and teams of two to five tie into a rope equally spaced. If someone begins to fall the other members of the team perform a self-arrest to stop the fall and then attempt a rescue.
Drownings are especially likely when accompanied by head injuries (which may render people unconscious), in very cold water (which can sap energy quickly), or in white water (which may be so frothy that it is impossible to float, or even swim, to the surface).
When walking beaches or crossing estuaries, it is essential to be aware of the tides.
Travelers may become lost, either if a group cannot find its way or if an individual 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. The absence of clearly marked trails increases the risk of losing one's way.
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 procedure 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 and compass, and knowing how to use them, will decrease the risk of getting lost. Likewise, a Global Positioning System may prove invaluable, as it can pinpoint a traveler's location, revealing his exact position and the direction to roads, services, and inhabited areas. Most GPS devices can also be designed to mark one's path on a map, making it easy to backtrack. Family Radio Service, General Mobile Radio Service, and amateur radios operating on the "2 meters" band may help maintain communication. Flashing lights, signal mirrors, and whistles are low-tech emergency signals.
Without a distant focal point, such as a mountain top, or the sun or moon, people who are lost can sometimes wander in circles.
Metabolic imbalances can affect general functioning and lead to other injuries.
In many areas, adventurers may encounter large predatory animals such as bears 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 may behave unexpectedly, even aggressively, and could infect a human with rabies by biting.
Venomous animals, including snakes, scorpions, spiders and bees, may cause harm either directly or through anaphylactic shock. Overall, the greatest danger is often from insects, such as mosquitoes, ticks and fleas, which carry communicable diseases.
Surface water in the wilderness can contain viruses, bacteria or parasites. The latter two can cause dysentery 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.