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Altitude Sickness

What would happen to you if you were taken immediately to the summit of Mt. Everest? The answer is you would pass out, and likely die within minutes. So why, then, can people summit Everest without oxygen? The answer to this lies in the understanding of oxygen, pressure, and your body’s ability to acclimatize over time. In general, the percent of oxygen in the air stays the same with altitude, however, the partial pressure of the oxygen in the air mixture decreases. Although overly simplistic, this means that as we gain altitude, the molecules of oxygen are more spread out and our body’s ventilation systems do not work as well. Over time, our body can adapt to lower pressure and therefore someone who is properly acclimatized can withstand much higher altitudes than someone who is not.

Acute Mountain Sickness (AMS) is the term used to describe illness related to altitude. Unfortunately, the symptoms of AMS are similar to many other illnesses. However, crews and individuals that live at lower elevations (usually below 4,000 feet) and are working and sleeping above 6,500 feet are at risk for AMS. It is rare to experience AMS below 8,000 feet, however, about 50% of people will experience at least a mild form of AMS above 10,000 feet. AMS should be considered if an individual:

  1. Recently traveled to a higher elevation (generally above 8,000 feet) AND

  2. Has a headache AND

  3. Has other symptoms including:

    1. Dizziness or lightheadedness

    2. Fatigue or weakness

    3. Nausea/vomiting/anorexia

    4. Insomnia

The most severe types of altitude related illness are a consequence of fluid buildup and swelling in either the brain or the lungs. These conditions are called high altitude pulmonary edema (HAPE) and high altitude cerebral edema (HACE). With HAPE, individuals experience AMS in addition to coughing and severe shortness of breath. With HACE, individuals experience AMS in addition to confusion, seizures, and other mental status changes.

Prevention of AMS, HACE, and HAPE is done by slowly acceding to altitude over several days; working high and sleeping low; and good nutrition and hydration.

Treatment of AMS ranges depending on severity. For mild symptoms, generally rest and hydration with some moderate decent in altitude for one or two days will allow for complete recovery and the ability to continue to work at altitude. For significant AMS, HACE, or HAPE, immediate decent, and evacuation is necessary.

Other examples include:

  • High altitude cerebral edema (HACE) is a severe and potentially fatal condition associated with high altitude illness that is often thought of as a late or end-stage AMS.

  • High altitude pulmonary edema (HAPE) is a severe form of high altitude illness that, if left untreated, can lead to mortality in 50 percent of affected individuals. It occurs secondary to hypoxia and is a form of noncardiogenic pulmonary edema. It is characterized by fatigue, dyspnea, and a dry cough with exertion.

Discussion Questions:

Where on this fire, your home unit or areas in the country might you or  your crew be at risk for developing AMS? What should you do to prevent/prepare? What should you do if symptoms develop?

 

Category
Firefighter Health & First Aid
References
CDC High Altitude Travel and Altitude Illness

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NWCG Committees Observe Suicide Prevention Awareness Week: September 7-13, 2025

Date: Sep 5, 2025
Questions? Please contact:
Mental Health Subcommittee

The NWCG Mental Health Subcommittee (MHSC) and Risk Management Committee (RMC) recognize the unique challenges and demands faced by the wildland fire community. The MHSC and RMC know that we are all stronger together and believe in fostering a culture of support, understanding, and resilience.

Suicide Prevention Awareness encourages us to actively connect with and support each other. For more information that could make a difference for yourself or someone else please review the materials and resources provided for the 2025 Suicide Prevention Awareness Week.

References:

2025 Suicide Prevention Awareness Week Materials and Resources

NEW! Incident Performance and Training Modernization Story Map Now Available

Date: Aug 26, 2025
Questions? Please contact:
National Wildfire Coordinating Group

NWCG is excited to announce the launch of the Incident Performance and Training Modernization (IPTM) Story Map, a new interactive resource that showcases how NWCG is transforming wildland fire training and qualifications through a performance-based system.

Since its launch in 2023, IPTM has made major strides in updating how we manage incident positions:

  • 36 incident positions now have new Incident Position Standards and Next Generation Position Task Books available for field use
  • 6 more incident positions are nearing completion
  • 111 total incident positions are being analyzed through the IPTM initiative

The Story Map guides you through the IPTM process, highlights key accomplishments, and outlines what’s ahead. Whether you are a trainer or a trainee, this tool offers valuable insight into the modernization effort shaping the future of wildland fire training and qualifications.

This effort would not be possible without the contributions of NWCG staff, NWCG committees, and hundreds of subject matter experts across the wildland fire community.

References:

IPTM Story Map

Incident Performance and Training Modernization Webpage

NEW! S-290, Intermediate Wildland Fire Behavior (Blended) Available Now

Date: Aug 15, 2025
Questions? Please contact:
Fire Behavior Subcommittee

NWCG is excited to announce that the S-290, Intermediate Wildland Fire Behavior (Blended) training is now available on the Wildland Fire Learning Portal. S-290 (Blended) training combines online training and instructor-led training components that support individuals working towards any Single Resource Boss or Fire Effects Monitor incident qualifications.

This second course in the series collectively serves to develop fire behavior prediction knowledge and skills, and provides more detailed information on fuels, weather, and topography that affect wildland fire behavior for safety purposes.

Students are required to finish the prerequisite S-190, Introduction to Wildland Fire Behavior, before enrolling in S-290, Intermediate Wildland Fire Behavior (Blended).

References:

S-290, Intermediate Wildland Fire Behavior (Blended)

S-190, Introduction to Wildland Fire Behavior

Wildland Fire Learning Portal

NEW! S-271, Helicopter Crewmember (Blended) Now Available

Date: Aug 14, 2025
Questions? Please contact:
Interagency Helicopter Operations Subcommittee

The S-271, Helicopter Crewmember (Blended) is now available. Developed through the Incident Performance and Training Modernization (IPTM) effort, this training supports individuals working towards Helicopter Crewmember (HECM) incident qualifications. 

S-271, Helicopter Crewmember (Blended) training combines online training and instructor-led training components. This course is designed to provide students with the knowledge and skills necessary to perform the duties of the HECM position, as described in the NWCG Incident Position Standards for Helicopter Crewmember, PMS 350-22.

Any changes to qualification pathways will take effect with the next update of the NWCG Standards for Wildland Fire Position Qualifications, PMS 310-1, scheduled for January 2026.

References:

S-271, Helicopter Crewmember (Blended)

NWCG Helicopter Crewmember (HECM) Position Page

Wildland Fire Learning Portal