Photo Credit: Have you ever seen a group of people walking around a track with what looked like 45 pounds? They were probably taking the “pack test” to work on wildland or prescribed fires. Photo by Jamie Mobley, Bureau of Land Management

“What did the IC say about the fuel models in the area where we’ll be performing burn out operations? I can’t wait to get my red card and work on my faller quals!”

“The fire behavior forecast suggests that it’ll be weeks until we contain the fire, but thanks to the eastern fire break and the lack of aerial fuels, we’re in relatively good shape.”


No matter how hard fire managers and communicators try, we’re bound to use a word or two that the general public doesn’t understand when it comes to wildfire.

With wildfire season underway, here’s a quick refresher on commonly used wildfire terms; using definitions from the National Park Service/USDA Forest Service wildfire terminology glossary:

Already fluent? I expect that many of our readers already speak fire-ease quite well; if that’s you, consider sharing this post with your local community or a new practitioner!

Common Wildfire Terminology

Aerial fuels: All live and dead vegetation in the forest canopy or above surface fuels, including tree branches, twigs, cones, snags, moss and high brush.

Burning index: An estimate of the potential difficulty of fire containment as it relates to the flame length at the most rapidly spreading portion of a fire’s perimeter.

Command staff: The information officer, safety officer and liaison officer [working on a wildfire]. They report directly to the incident commander and may have assistants.

Contain a fire: A fuel break around the fire has been completed. This break may include natural barriers or manually and/or mechanically constructed line.

Defensible space: An area, either naturally or human-made, where material capable of causing a fire to spread has been treated, cleared, reduced or changed to act as a barrier between an advancing wildland fire and the loss of life, property or resources. In practice, “defensible space” is defined as an area a minimum of 30 feet around a structure that is cleared of flammable brush or vegetation.

Smoke carrying through the trees near a home. There is a buffer ("defensible space") between the home and its surrounding forest.

Thanks to defensible space (minus the firewood on the deck), this home withstood recent wildfires. Credit: Frank Riley, Chestatee/ Chattahoochee Resource Conservation and Development Council

Drip torch: A hand-held device for igniting fires by dripping flaming liquid fuel on the materials to be burned; consists of a fuel fount, burner arm and igniter. Fuel used is generally a mixture of diesel and gasoline.

Drip torch

A drip torch is a hand-held device used to ignite fires by dripping flaming liquid fuel on the materials to be burned. Credit: Clay Carrington

Fire behavior forecast: A prediction of probable fire behavior, usually prepared by a fire behavior officer, in support of fire suppression or prescribed burning operations.

Fire break: A natural or constructed barrier used to stop or check fires that may occur, or to provide a control line from which to work.

Fire triangle: Instructional aid in which the sides of a triangle are used to represent the three factors (oxygen, heat and fuel) necessary for combustion and flame production; removal of any of the three factors causes flame production to cease.

Pack test: A test used to determine the aerobic capacity of fire suppression and support personnel and to assign physical fitness scores. The test consists of walking a specified distance, with or without a weighted pack, in a predetermined period of time, with altitude corrections.

Personnel protective equipment (PPE): The proper equipment and clothing needed to mitigate the risk of injury from, or exposure to, hazardous conditions encountered while working. For those working with wildfire, PPE includes, but is not limited to, 8-inch high-laced leather boots with lug soles, fire shelter, hard hat with chin strap, goggles, ear plugs, aramid shirts and trousers, leather gloves and individual first aid kits.

Fire practitioners wearing personal protective equipment while working on a prescribed fire

For people working on a prescribed or wildland fire, having a fire shelter (worn on their back) is part of their “personal protective equipment.” Credit: Penny Morgan, University of Idaho

Red card: A fire qualification card issued to fire-rated persons showing their training needs and their qualifications to fill specified fire suppression and support positions in a large fire suppression or incident organization.

Red flag on the beach

Red flags mean different things in different places. By the ocean, they typically refer to dangerous surf/swimming conditions. In the realm of wildfire, a “red flag warning” refers to weather patterns that increase the risk of wildfire. Credit: ashleigh290 shared via Flickr Creative Commons

Red flag warning: A term used by fire weather forecasters to alert forecast users to an ongoing or imminent critical fire weather pattern.

Swamper: (1) A worker who assists fallers and/or sawyers by clearing away brush, limbs and small trees. The swamper carries fuel, oil and tools and watches for dangerous situations. (2) A worker on a dozer crew who pulls winch line, helps maintain equipment, etc., to speed suppression work on a fire.

Wildland-urban interface: The line, area or zone where structures and other human development meet or intermingle with undeveloped wildland or vegetative fuels.

These terms and definitions were selected from one of the many wildfire glossaries out there. The National Wildfire Coordinating Group also has a comprehensive glossary, if you’re looking for another source.

What about “Types?”

Type 5, Type 2, Type 1 … the types of wildfire incidents are a whole other can of worms. Check out this run down of the different types of incidents.

You Tell Me

What wildfire terms are commonly misunderstood? What’s the one term that everyone should understand? Provide your thoughts in the comment section below!

Editor’s note: The definitions provided above are not necessarily the best definitions to use when conducting public outreach.

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