The dangers
A campfire may burn out of control in two basic ways: on the ground or in the trees. Dead leaves or pine needles on the ground may ignite from direct contact with burning wood, or from thermal radiation. Alternatively, airborne embers (or their smaller kin, sparks) may ignite dead material in overhanging branches. This latter threat is less likely, but a fire in a branch will be virtually impossible to put out without firefighting equipment, and may spread more quickly than a ground fire.
Embers may simply fall off of logs and be carried away by the air, or they may be ejected at high speed by exploding pockets of sap. With these dangers in mind, some locales prohibit all open fires, particularly during times of the year particularly prone to wildfires.
Campfires are prohibited in many public camping areas. Public areas with large tracts of woodland usually have signs indicating the fire danger, which usually depends on recent rain and the amount of dead growth; when the danger is highest, all open fires are prohibited. Even in safer times, it is common to require registration and permits to burn a campfire. Such areas are often viewed by rangers, who will dispatch someone to investigate any unidentified plume of smoke.
Finding a site, and other safety measures
Ideally, every fire should be lit in a fire ring. If a fire ring is not available, a temporary fire site may be constructed. One way is to cover the ground with sand, or other soil mostly free of flammable organic material, to a depth of a few centimeters. The area of sand should be large enough to safely contain the fire and any pieces of burning wood that may fall out of it. Sand piles should be scattered after the fire has been put out. If the topsoil is moist, it may suffice to simply clear it of any dead plant matter.
Fire rings, however, do not fully protect material on the ground from catching fire. Flying embers are still a threat, and the fire ring may become hot enough to ignite material in contact with it.
No fire should be lit close to trees, tents or other fire hazards. This includes overhanging branches; some carry dead, dry material that can ignite from a single airborne ember. In addition, a fire may harm any roots under it, even if they are protected by a thin layer of soil. Conifers run a greater risk of root damage, because they lack taproots and their roots run close to the surface. Fires also should not be lit on bare rocks, because the ash will leave a black stain.
An additional safety measure is to have sand and water on hand to smother and douse the fire if it does get out of the fire pit. It is wise to gather these materials before they are actually needed.
Having found a suitable site and gathered materials, the fire-builder has a variety of designs to choose from. A good design is very important in the early stages of a fire. Most of them make no mention of fuelwood - in most designs, fuelwood is never placed on a fire until the kindling is burning strongly.
One of five problems can prevent a fire from lighting properly: wet wood, wet weather, too little tinder, too much wind, or a lack of oxygen. Rain will, of course, douse a fire, but a combination of wind and fog also has a stifling effect. Metal fire rings generally do a good job of keeping out wind, but some of them are so high as to impede the circulation of oxygen in a small fire. To make matters worse, these tall fire rings also make it very difficult to blow on the fire properly.
Steady, forceful blowing may be in order for a small fire in an enclosed space that has mysteriously slowed down, but blowing may extinguish a fire if it is done abruptly or when it is not needed. Most large fires easily create their own circulation, even in unfavorable conditions, but the variant log-cabin fire-build suffers from a chronic lack of air so long as the initial structure is maintained.
Once the large kindling is burning, all of the kindling should be put on the fire, save for one piece at least a foot long. This piece is useful later to push pieces of fuelwood where they are needed. Once all of the kindling is burning, the fuelwood should be placed on top of it (unless, as in the rakovalkea fire-build, it is already there). For best results, two or more pieces of fuelwood should be leaned against each other, as in the tipi fire-build.
Most campfires, though, are lit exclusively for recreation. People tend to find something fascinating about flames and glowing coals, so a campfire is usually an agreeable way to pass the time from dusk to bedtime, particularly for those in a pensive mood. Campfires are also good venues for intimate conversation and storytelling; stories about poltergeists are particularly popular.
Another traditional campfire activity involves impaling marshmallows on sticks or uncoiled coat hangers, and roasting them over the fire. A roasted marshmallow smashed between two Graham crackers with a piece of chocolate (traditionally Hershey's) is called a S'more. (The name is allegedly derived from the words some more.)
Large amounts of water are indispensable for extinguishing a fire. To properly cool a fire, water should be poured on all the embers, including places that are not glowing red. The water will boil violently and carry ash in the air with it, dirtying anything nearby but not posing a safety hazard. The water should be poured until the hissing noises stop. Then the ashes should be stirred with a stick to make sure that the water has penetrated all the layers; if the hissing continues, more water should be added.
If water is scarce, sand may be used. The sand will deprive the fire of oxygen quite well, but it is much less effective than water at absorbing heat. Once the fire has been covered thoroughly with sand, all water that can be spared should be poured on it, and the sand stirred into the ash.
Finally, in lightly-used wilderness areas, it is best to replace anything that was moved while preparing the fire site, and scatter anything that was gathered, so that it looks as natural as possible.Types of fuel
There are, by conventional classification, three types of material involved in building a fire without manufactured fuels.
The gathering of fuel in natural areas is often restricted. Cutting of living trees is almost always forbidden - but neither is it very useful, because sap-filled wood does not burn well. Squaw wood (dead parts of standing trees) may also be prohibited. Wood lying on the ground is usually permitted.Building the fire
Lighting the fire
Once the fire is built, the next step is to light the tinder, using either a match or a lighter. A reasonably skillful fire-builder using reasonably good material will only need one match. The tinder will burn brightly, but be reduced to glowing embers within half a minute. If the kindling does not catch fire, the fire-builder must gather more tinder, determine what went wrong and try to fix it.If there are no matches
There are several ways to light a fire without a match. All of them work with only the lightest and most flammable tinder, such as toilet paper or tampons.Campfire activities
Campfires have been used for cooking since time immemorial. However, portable stoves have all but replaced campfires in this regard. For cooking information, see cooking on a campfire. Other practical, though not commonly needed, applications for campfires include drying wet clothing, alleviating hypothermia and use as a distress signal.Extinguishing the fire
Leaving a fire unattended is dangerous! Any number of accidents might occur in the absence of people, leading to property damage, personal injury or possibly a wildfire. Ash is a very good insulator, so a fire left overnight will only lose a fraction of its heat.