A smokejumper is a wildland firefighter who is trained to deploy from fixed wing aircraft. Several nations including the United States, Canada, Russia, and Mongolia maintain large numbers of smoke jumpers on the national payroll to handle outbreaks of fires in remote regions which are difficult to access. This job, as you might imagine, can be extremely dangerous, and it is also considered to be very glamorous by some people, since it combines the skills of firefighting with the daring to leap from aircraft into the path of an oncoming fire.
As a career, smokejumping dates back to around the late 1930s, when several countries started experimenting with using smokejumpers to handle forest fires. Typical smokejumping teams handle small fires, working quickly to put them out so that they do not spread; a smokejumping team may also decide to call in reinforcements if it becomes clear that they will not be able to control the fire. They typically work in rugged, remote terrain which is difficult to access, giving firefighting crews an edge on fighting a fire before it gets big and dangerous.
Some people think that a career as a smokejumper must be awfully exciting, and it certainly is during the summer months, when flareups are extremely common. Smokejumpers remain on call in shifts in various locations around the world, ready to deploy to regional and distant fires, and actually much of their work is fairly mundane, since they put out up to 90% of the fires they tackle before these fires get big enough to require assistance.
While the cost of training and maintaining an individual smokejumper is high, some nations believe that the cost is worth it, as the associated damages from an out of control fire can be much higher. Smokejumpers are also cheaper than one might imagine to maintain, classically utilizing fixed wing aircraft, rather than expensive helicopters, for example, and often working with very basic tools.
While the perception of this job is that it is very dangerous, statistics seem to suggest that it is no more dangerous than other branches of the firefighting field. This is because smokejumpers train extensively, and constantly participate in exercises to ensure that their skills are sharp. In addition to being thoroughly trained in fire safety, smoke jumpers are also experienced parachutists; some are former military members, using their training and skills in a new context after they leave the military.
If you are interested in a career as a smokejumper, you can apply to regional firefighting schools which offer smokejumper training. Some prefer smokejumpers with wildland firefighting experience and/or experience as pilots or parachutists, while others are willing to train students from scratch. In both cases, you should be at peak physical condition, and willing to work and train hard for several years before you are allowed to work on the front lines of firefighting.