For two summers in the 1960s I fought wildland fires as a member of a crew, first with the State of Oregon Forestry Department and then with the East Lane Fire Protection Association. Later, I spent a summer in Washington state as a “smokejumper” who parachuted into areas near small fires and contained them before they spread. Although wildland firefighting today is quite different than it was in the 1960s and 1970s, my experiences provide insight into the many industrial hygiene concerns associated with this work, including the protective clothing worn by wildland firefighters and why it differs from that worn for structural firefighting.

FIRE CREW TRAINING Part of the training given to my crews was how to “line” a fire—that is, deprive it of fuel through digging and the removal of vegetation. The tools we used were a shovel; a heavy-duty hoe known as a hazel hoe; a grub hoe; a Pulaski, which has a wooden handle and a head that combines an axe and an adze; and a regular axe. Some crew members also had chainsaws. The Oregon State Forestry crew did not use water to line fires; the East Lane crew had a water tanker available. But both crews learned how to dig a trail around a fire to stop it from spreading without water.

The clothing we used on these crews consisted of cotton underwear; a cotton shirt; long, black jeans; leather gloves; a large bandana around our neck, which we could pull up over our mouth and nose; and leather boots with heavy socks underneath. Hardhats were mandatory and protected us from falling limbs or debris. The pants were “stagged,” or cut off the cuff, to prevent broken branches from becoming stuck in the cloth and tripping us. Each of us also carried a canteen, as it was extremely important to drink when fighting wildfires.

SMOKEJUMPING In 1972 I became a smokejumper out of the North Cascades Smokejumper Base in Winthrop, Washington. Smokejumpers were deployed to small fires, usually caused by lightning strikes, that typically affected only a single tree. At that time, these fires did not spread quickly, and a crew of only two smokejumpers could extinguish them. Smokejumpers wore a jump suit, which was very heavy and had pockets equipped with 200 feet of “letdown tape” that allowed the smokejumper to rappel out of a tree if the parachute got hung up. The suit was equipped with a sewn-in nylon line that protected the smokejumper from groin injuries caused by landing in trees. Smokejumpers also had a reserve parachute with a knife on top for cutting things after landing or disentangling suspension lines following exit from the aircraft. A helmet with a wire mask kept limbs and branches from striking the face.

The protective clothing smokejumpers wore underneath the jumpsuit was similar to what firefighting crews wore, except that smokejumpers had fire shirts, and their boots were made of much thicker leather. Drinking water was dropped to us as part of our firefighting kit, which included a chainsaw for cutting down burning trees. Two-person smokejumper crews had a radio for contacting the aircraft overhead (and our headquarters if we were close enough).

Smokejumper training included a basic fire behavior school. We learned about the “fire triangle”­—its need for fuel, oxygen, and heat; how heat is transferred via conduction, convection, and radiation; and how fuel, weather, and topography influence the spread of fire. We learned that fuel in a forest had a heat ignition temperature of approximately 560 F. Heat transfer happened due to conduction, convection, and radiation, and fires spread due to fuel, weather, and topography. We were given the following instructions: 1. Keep informed about fire weather conditions and forecasts. 2. Know what your fire is doing at all times. Observe personally and use scouts. 3. Base all actions on the current and expected behavior of the fire. 4. Have escape routes for everyone and make them known. 5. Post a lookout when there is possible danger. 6. Be alert, keep calm, think clearly, and act decisively. 7. Maintain prompt communications with your team, your boss, and adjoining forces. 8. Give clear instructions and be sure they are understood. 9. Maintain control of your team at all times. 10. Fight the fire aggressively but provide for safety first.

We also learned about “bummer indicators”—that is, situations in which firefighters need to re-evaluate conditions and consider evacuating the area or deploying their fire shelter. One bummer indicator was building a fire line downhill toward a fire, because fires burn very fast uphill. (Later, I investigated a fatal incident where loggers working uphill from a fire were overtaken.) Other bummers were a change in wind direction, a feeling that the weather was getting hotter and drier, and areas to avoid if possible: hillsides, where debris from a rolling fire could fall and ignite; difficult terrain that slowed travel; and heavy forest with unburned fuel between you and the fire. Being in country you hadn’t seen in the daylight was another bummer.

The types of fires we see now, with the crowning and extremely fast movement of the fire at the head, pose extreme hazards. Before fires behave like this, crews need to be pulled from the fire lines and attacks made by other means, such as air tankers.

Recent articles in Smokejumper magazine describe changes in tactics that illustrate difficult tradeoffs. One author suggests that the U.S. Forest Service has prohibited nighttime firefighting for safety reasons, even though it is well known among wildland firefighters that fires “lay down” at night, when weather conditions change and winds abate. Another article published in January 2022 describes the refusal by fire mangers to let smokejumpers attack a small fire; when the fire got out of control, huge numbers of firefighters were needed:

There are times when firefighters are trapped and must resort to sheltering. The U.S. Forest Service requires wildland firefighters to carry specialized shelters made of aluminum and fiberglass that provide protection in temperatures above 1,000 F. Specialized training is necessary on how to climb in and seal the shelter, and how to breathe effectively (firefighters are instructed to keep their heads four inches above the ground inside the shelter).