NIOSH releases report on CR 337 fire, fatality in Texas

Caleb Hamm
Caleb Hamm

The National Institute for Occupational Safety and Health (NIOSH) has released a report on the death of BLM Hotshot crewmember Caleb Hamm, who died from hyperthermia, a heat related illness. (The most severe form of hyperthermia is heat stroke.)  Mr. Hamm was working on the CR 337 fire near Mineral Wells, Texas with the Bonneville Interagency Hotshot Crew when he collapsed and died July 7, 2011.

His parents, including his mother, Lynette Hamm, believe the official BLM report on the fatality has errors and suspects that the agency has not been completely forthcoming in an attempt to hide errors or mistakes in judgement. Ms. Hamm has said she wants all the facts to be disclosed so that other parents of firefighters will not have to bury their sons and daughters.

A television station in Utah, KSL, did a story on the incident.

Here is an excerpt from the article at KSL TV, which quotes Martin Buzbee, a city official from Mineral Wells, Texas who acts as the GIS mapping coordinator. :

…”I kept waiting and waiting for a medevac helicopter to be flown in and take care of the patient,” Buzbee said.

The medical helicopter and ambulance were parked just a few miles away. They were supposed to be called in according to the BLM’s own emergency plan, but the BLM was trying to use its own helicopter.

“They were reconfiguring a helicopter from the fire: from dropping water with a bucket, taking the bucket off and to try to medevac the patient in,” Buzbee described.

Eventually, the BLM did call in the civilian helicopter and ambulance. Official reports said the delay was 20 minutes; however, Buzbee believes it was more like 45 minutes.

Hamm was taken by ambulance from Drop Point Twenty and pronounced dead at the hospital. The incident was investigated by the National Institute for Occupational Safety and Health. NIOSH concluded the 20 minute delay did not contribute to Hamm’s death. But Buzbee believes if the BLM had called the medical helicopter to the top of the hill immediately, it might have made all the difference.

Below is an excerpt from the NIOSH report which was released May 14, 2012.



On June 23, 2011, a 23-year-old male seasonal wildland fire fighter (FF) on an interagency hot shot crew (IHC) deployed from his duty station in Utah to fight wildland fires in Georgia and Texas. After fighting fires in Georgia for 4 days, the crew was dispatched to Texas. After travelling for 3 days, then staging for 3 days, the crew began fire fighting on July 4, 2011.

On the morning of July 7, 2011, the FF was assigned swamper duties (clearing limbs after tree-cutting) to construct a fireline followed by cold trail operations (a component of mop-up) with a hand tool. After lunch, the FF refilled his water supply and continued securing the fireline and mopping up for about 1.5 hours. After being left alone for a short period of time, the FF was found unconscious at approximately 1550 hours. The weather was sunny and hot: a temperature of 105 degrees Fahrenheit (°F), relative humidity of 24% with minimal wind (1 to 3 miles per hour).

Initial assessment by the crew’s emergency medical technician (EMT) suggested the FF suffered from heat-related illness (HRI). Air Attack was notified as the crew EMTs provided basic HRI care at this remote location (the FF’s pack and shirt were removed, he was doused with water, and a tarp was held up for shade). Local emergency medical service (EMS) units (ambulance and Air Evacuation helicopter) were not notified of the incident for about 20 minutes due to uncertain drop point coordinates. This delay, however, did not delay advanced life support (ALS) treatment because it took 45 minutes to extract the FF to the drop point where the local EMS units were waiting.

Approximately 30 minutes after his collapse, the FF’s condition deteriorated; respiratory arrest was followed by cardiac arrest, and cardiopulmonary resuscitation (CPR) was begun.

Approximately 15 minutes after his cardiac arrest the FF arrived at the drop point and the local, ambulance and Air Evacuation units initiated advanced life support (ALS) but their treatment protocols for exertional heatstroke did not include cold/ice water immersion therapy. When the FF arrived at the hospital ED a core temperature of 108° F was documented and ALS continued for an additional 5 minutes. At 1703 hours the attending physician pronounced the FF dead and resuscitation efforts were stopped.

The autopsy report listed the cause of death as “hyperthermia.” NIOSH investigators agree with the Medical Examiner’s assessment. NIOSH investigators conclude that the FF’s hyperthermia was precipitated by moderate to heavy physical exertion in severe weather conditions. These factors led to exertional heatstroke.

All of the IHC members were exposed to heat stress (hot environmental conditions). Most IHC members interviewed by NIOSH reported symptoms consistent with HRI (feeling hot, feeling tired/fatigued/exhausted, weakness, headache, or nausea). Although indicators of heat strain were not measured (core body temperature, heart rates), on the basis of the environmental conditions and the reported symptoms, NIOSH investigators concluded that many of the IHC crewmembers had mild to moderate HRI.

Fatal exertional heatstroke is extremely rare among wildland fire fighters; this was the first reported case in the Agency’s 65-year history and only the second reported federal wildland fire fighter to die from heatstroke according to wildland fire service records. Agency records, however, show that less severe cases of HRIs and dehydration are more common; 255 cases occurred over the past 12 years. NIOSH considers cases of HRI to be “sentinel health events” [NIOSH 1986]. Sentinel health events are preventable diseases, disabilities, or deaths whose occurrence serves as a warning signal that preventive or therapeutic care may be inadequate [Rutstein et al. 1983].

To prevent HRI and heatstroke, a number of organizations have developed guidelines for determining when environmental conditions are too hot to continue training, sporting, or work activities. The environmental conditions during this incident exceeded these guidelines. NIOSH investigators offer the following safety and health recommendations to reduce heat stress, heat strain, and prevent future cases of HRI and exertional heatstroke among wildland fire fighters. Implementing these recommendations will demonstrate a continuing commitment to improve the safety culture of the wildland fire service.

  • Strengthen the Agency’s current heat stress program with the following components:
    • instruct fire fighters and command staff that hydration alone will not prevent HRI;
    • develop re-acclimatization schedules for wildland fire fighters not working for more than 4 days;
    • measure environmental heat conditions using a Wet Bulb Globe Thermometer (WBGT);
    • when heat stress criteria are exceeded, discontinue physically demanding training according to the guidelines developed independently by the United States (U.S.) Army/Air Force and American College of Sports Medicine (ACSM);
    • when heat stress criteria are exceeded, require hourly work/recovery cycles according to NIOSH and ACGIH guidelines, particularly when the operation does not involve rescue operations;
    • when heat stress screening criteria are exceeded, consider monitoring fire fighters for signs of heat strain;
    • when heat stress screening criteria are exceeded, consider a bimodal shift or two shifts;
    • consider incorporating a screening checklist for heatstroke risk factors into the Agency’s medical screening and medical examination program;
  • Always work in pairs and/or be in direct communication with crewmembers.
  • Promptly alert local EMS units of a medical emergency per Incident Command protocols.
  • When exertional heatstroke is suspected, inform responding EMS units of the potential need for cold/ice water immersion therapy.
  • Seek input from crewmembers and frontline supervisors about removing barriers, real or perceived, to reporting or seeking medical attention for heat strain or HRI.
  • Consider cases of HRI, particularly severe cases such as heatstroke or rhabdomyolysis that result in death or hospitalization, as a sign that the current heat stress program is inadequate.
  • Consider incorporating members of the Department’s Safety Office into the Operations Management Team.
(end of excerpt)


It is interesting that one of the NIOSH recommendations was to use a Wet Bulb Globe Thermometer (WBGT). In 1972 when I was on the El Cariso Hot Shots, a research organization paid the salary of one of the crewmembers that year, Tom Sadowski, to monitor three people on every fire, recording their pulse at regular intervals while they worked, what they ate, weather conditions, and other criteria. Tom also carried a WBGT, which was a thermometer with a three-inch black sphere on the end which had to be wet when readings were taken. The concept was that as the water evaporated the WBGT took into account the ambient temperature, the effect of wind on the evaporation, cooling from evaporation, and radiant heat from the fire or the sun. I don’t know what became of the research and the huge amount of data that Tom collected. Maybe there is a paper floating around out there somewhere.

UPDATE: Ken, in a comment, found the report from the study. The paper was first published in 1974 and a summary appears in a 1975 edition of Fire Management on page 16.

The recommendations the researchers made still seem applicable today. Interestingly, they suggest using a wet globe thermometer in order to “recognize heat stress situations”, which is similar to one of the recommendations made in the recent NIOSH report. This recommendation has been on the books for about 38 years. Maybe it’s time the agencies involved in wildfire suppression took action on it.

Perhaps every safety officer on a fire should have one when heat stress is a possibility. It might save a life.

Google Search found WBGTs listed for sale at $150 to $230.


UPDATE May 16, 2012:

The Wildland Fire Lessons Learned Center and the International Association of Wildland Fire are hosting a webinar titled Wildland Firefighter Heat Illness Awareness and Prevention on May 17 at 1:00 p.m. PDT. More info HERE.



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Author: Bill Gabbert

After working full time in wildland fire for 33 years, he continues to learn, and strives to be a Student of Fire.

32 thoughts on “NIOSH releases report on CR 337 fire, fatality in Texas”

  1. Much thanks to you, Bill, for helping to get the true story out there. More than anything else, his father and I want measures taken so this never happens again. All firefighters need to have the assurance their crewmates have their back when they need medical help. We all working together can help make a difference. That would have been what Caleb wanted, to help the next firefighter who needs it.

  2. Very sorry for your loss, Mrs Hamm. As I have said before, no line of duty death is acceptable.

    In humid areas, professional and many college football programs have their Trainers monitor the atmposphere with a WBGT and practice is cancelled when the combination of factors reaches a point where the players can no longer cool themselves by sweating. The use of a WBGT has trickled down to some high school programs after a number of fatalities of high school football players.
    I assume they are monitoring all outdoor sports, not just football.

    A question: Could there come a time when the WBGT is such that we pull fireighters off the line because they can no longer cool themselves due to the humidity?

  3. It may be a rhetorical question to you, but until you live the nightmare we are, the question is real.

  4. The real point to our concerns is this: the moment he said he was hot, that was the “golden” moment that should have been utilized by calling for emergency medical treatment. Would he have died? We will never know, because he was hidden away in the “green” part. Emergency help wasn’t called for. Who is responsible for making the call on whether emergency treatment is needed? The crew leader, the squadleader, who?? And if they leave that decision up to them, who have little medical training, where does that leave the next guy/girl who speak up and say they are don’t feel well? In the NISOH report, from the CDC, there is documented persons saying they felt they could not speak up in that crew for fear of losing their job. And the BLM doesn’t want to say “for privacy reasons” that anyone received any disciplinary actions. Well, guess what? The assistant super isn’t there any longer, we know that for a fact.
    If our son would have been found with a knife in his back in that ravine, that would have been called murder, and in investigation would happen. Who answers for this? Because this will keep happening, rest assured, because these guys are being allowed to keep working with, yes–your loved ones.

  5. Bill,

    The study that you are referencing is in “Fire Management Notes” – Volume 36, No. 3.

    It was titled, “Firefighter’s Work Environment and Physical Demands Studied”.

    The study was funded in 1970 with the findings published in June, 1974.

    Here is the info: “A report that discusses our findings in further detail is available from the Equipment Development Center in Missoula, Mont. Ask for project record FIREFIGHTER PHYSIOLOGY , June 1974”.

  6. Ramberg, R. 1974. Firefighters physiological study. Tech. Rep. 7551-2205-MTDC. Missoula, MT: U. S. Department of Agriculture,
    Forest Service, Missoula Technology and Development Center.

  7. Wow. Great find, Ken. The recommendations the researchers made still seem applicable today. Interestingly, they suggest using a wet globe thermometer in order to “recognize heat stress situations”, which is similar to one of the recommendations made in the recent NIOSH report. This recommendation has been on the books for about 38 years. Maybe it’s time the agencies involved in wildfire suppression took action on it.

    Perhaps every safety officer on a fire should have one when heat stress is a possibility.

  8. The Kestrels a lot of us carry, and I’m sure other brands of wx meters, can measure heat index, and would probably be more durable for field use. If a recognized guideline based on heat index were to be established, the equipment is already out there to take the measurements. The hardest part may be getting firefighters to admit that they’re overheated, and take a break, unless/until there’s a rule requiring it.

  9. There’s been a ton of heat stress and physiology work done over the years at MTDC, starting with the referenced work by Dick Ramberg, and continuing on to the 2011 Publication by Joe Domitrovich and Dr. Brian Sharkey titled “Heat Illness Basics for Wildland Firefighters.” We also started the semi-annual “Wildland Firefighter Health & Safety Report” in 2000 that has lots of good heat stress info over the years.It’s all available at The folks at the University of Montana under Dr. Brent Ruby have also done a lot of work monitoring the effects of prolonged hard and hot work on wildland firefighters. Another excellent bunch of research on heat stress on wildland firefighters was done by the Aussies under “Project Aquaris” in the 1990’s. They published a special edition on the IAWF International Journal of Wildland Fire on “Stress, Strain and Productivity of Men Suppressing Wildland Fires with Hand Tools” and then had a smaller, more user-friendly version put out as “Safe and Productive Bushfire Fighting with Hand Tools.” Their most “quotable” finding in my mind was that the purpose of wildland PPE “was to let heat out, NOT keep heat out.” About 2/3s of the heat that a firefighter is subjected to is metabolically generated, not from the fire. So much for the double-layering concept.
    Bottom line: heat stress in the business of wildland firefighting is not a new issue; let’s implement what we already know to help firefighters stay healthy and alive.

  10. I have admired Dick Mangan’s leadership in the wildland fire service. He is correct. Heat stress in the fire service is not new. He, and others at MTDC deserve much of the credit for funding and conducting some of that research. That literature is reviewed in the discussion section of the NIOSH report (attached at the website address). However, the wildland fire service needs to recognize that under severe environmental conditions, hydration, fitness, and acclimization is not enough prevent exertional heat stroke. There are well established work-rest cycles based on the heat generated by the work, the environmental conditons (as measured by WBGT), and the acclimitization of the individual. All of those guidelines (military, ACSM, NIOSH, ACGIH) would have precluded cold trailing work that afternoon in Texas. Adoping these work-rest cycles as a policy initiated would go a long way to not only preventing future cases of exertional heatstroke, but other less severe cases of heat-related illness and rhabdomyolysis.

  11. I think that city offical spoke incorrectly when he stated that the BLM wasted time by trying to reconfigure the current helicopter on scene from dropping water to be able to pick up a pt.

  12. Folks that are saying “facts are incorrect” need to specify why they are incorrect, let us know what the correct information is, and the source of their knowledge.

  13. I was the pilot of that helicopter that he was saying was trying to be re-configured.

  14. Br250r
    You might want to read the Serious Accident Investigation
    Factual Report
    CR 337 Fatality
    Bureau of Land Management
    Texas Forest Service
    Mineral Wells, Texas
    July 7, 2011. Plus I was on the fire and heard the TFS Regional Fire Coordinator’s multiple times on the radio requesting the status of the helicopter while it was being reconfigured. Why do we have an Initial Attack Plan with a medical plan on fires if we are not going to utilize it. Its time to quit playing cowboy and use the system.

  15. Thank you Fireprincess!!! You get totally where my hubby and I are coming from!! So many things went wrong, and the BLM doesn’t want to take any blame for any of it. Everyone just wants to say it wasn’t their fault, but if a plan is in place, and no one uses it?–well then, get ready, cause there will be lots more deaths.

  16. Bill,

    This topic tears me up. There are important lessons learned that are often lost through communication.

    I hope that everyone (family and agency employees alike) have the strength to get together some day at the Wildland Firefighter Foundation’s FAMILY FIRE Weekend.

    It provides a chance for healing and lessons learned, as well as a chance to be with MANY others who have experienced losses in the wildland fire service… both as family members and as agency employees who have lost close friends and co-workers.

    More often than not, at the Foundation, folks are able to share their grief and work towards shared solutions to a path forward while gaining support from others with similar experiences.


  17. I must apologize, I came off as trying to defend the BLM and the policies. I have to be clear that I am not.
    I have not read any reports other than the text and video that was posted on the Wildfire today website. I’m also not trying to dispute any other topics other than that as the pilot of the only helicopter on the scene contracted by the Texas Forest service we did not try to reconfigure my helicopter. I had a longline and a water bucket on the helicopter and was doing very fast, high water drops on Caleb and the crew helping him to cool the area down with a very light mist of water. I never landed the helicopter to reconfigure. Once I found the site from the air, and it was hard to find, I was able to put water down for them. When the EMS helicopter was enroute I put water on the drop site for dust abatment. After the EMS ship landed I was instructed by Air Attack to continue to go back and do water drops on a different part of the fire. I’am very sorry if I came across in a manner that was offensive, I did not intend for that to happen. I’m not sure why any report would say that I was trying to reconfigure and I’m not sure why someone listening to the radio thinks thats what happen as it didn’t. I never landed the helicopter.

  18. I have read sooo many comments on most of the articles. Believe me, the first investigation report was very correct. Caleb did say he was feeling hot and had a headache but only once when he was sat down. The report was just trying to say that that was the only time he spoke up that he wasn’t feeling well. The crew followed the medical plan. When a medical emergency happens, there is a chain of command that is followed. We called division about the emergency. The information was than radioed to air attack and relayed to medical. We do not call the ambulance or air evav helicopter direct. We did not have our own helicopter also. The niosh report was just the same as the other so all you people that think there is a cover-up, stop it. Radios we used, he was not left and forgotten until we got to the rigs, the reason he had not a lot in his stomach for the autopsy was because he vomited while we were giving him cpr. He had the first sighns of a heat related illness at the time he said something and we did what is proper, sit in shade, drink fluids and rest. We were all hot and tired. We all told the truth, the niosh investigation was a neutral way to evaluate what happend and it was the same. To all who have been saying otherwise, rumors will only get us farther away from healing. You all were not there, so stop saying “thus is what I heard”. We all who were there and told the truth are sick of it.

  19. Really? Then why won’t the crew meet us or speak to us? You all sure did accept our hugs and prayers one hour before the funeral, and told us “whatever you need, we will help you”. I call Bull**** alert on every one of you. With the exception of 2 of you, and you know who you are, the rest of you have disappeard off the radar. What about your fearless leader? Nope. Nada. What about Willie Almand? Nope. Nada. Oh, and by the way, we know he has been promoted to supervisor at the Modoc. They better watch their backs, hope to God we don’t hear of a death at that location. And no, the radios were not used at the first. That was told to us, and also in the report if you will read it. If radios had been used, maybe help would have been faster. No matter now though. And why wouldn’t Juan Palma ever speak with us after begging for meetings with him? He cancelled the first one, would never ever call us back for any others. Then, now that the NiOSH report is out, guess who wants to talk? And, you won’t see this in print anywhere, but we have a saved phone message which says “if you will only meet with us we will tell you who was with Caleb:” . So, guys, which is it? Was Caleb alone, or was he with someone, 10 months after the death, and you still can’t get your stories straight!!

  20. And if you were there, why not come out with your name, what are you afraid of?

  21. oh i remember what you are afraid of!! that’s right!! you all were told to keep your mouths shut the minute you landed in SLC. That’s right, it’s coming back to me now. And if you are a man, and going to do what’s right, come forward with your name and tell the truth for a change.

  22. The biggest indicator that all wasn’t right with this has been the hush-hush and the “I can’t give you my name or I will be in trouble” added on. If there wasn’t anything hinky going on, why not all of you “hotshots” come out and say who you are and what you have to say. You are big enough to face a forest fire, but not big enough to face a comrad’s mother. Shame on you.

  23. I just told you the truth. Its time to except it. We were never told to not talk to anyone. Never. The reason people are not giving out names is because of harassment. You are not excepting our statements. You have two reports that tell what happend. You have people that were there telling you that that is what happend. At this point you are going to believe what you want and no one will change your mind. Shame on you. Shame on all the emails sent out to with totally false info based on rumours. I’m sorry what happend. We live with it everyday.

  24. And just to make this crystal clear, we have NEVER directly spoken to was on site with him at the very beginning. Those person/s remain anonymous.

  25. One year ago today, Caleb, you went down after fighting for Texas lands. You were someone to look up to, someone others have worked towards emulating. Your memory never fades. Don’t worry, son, we are still working towards the truth for you. Your death will not be in vain. Some steps have been taken, but not enough. The fight continues!!

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