WHEN THE SMOKE NEVER CLEARS: A DOWNED RESPONDER'S PLIGHT WITH CO POISIONING

Marissa’s Story and the Hidden Epidemic:
Understanding the Neurotoxins Behind the Fog

By: Lennard M. Goetze

Photo courtesy: FF Marissa Halbeisen

Across the country, thousands of first responders and civilians are living with an invisible illness—neurological damage linked to smoke inhalation and carbon monoxide (CO) exposure. Often mistaken for stress, depression, or simple fatigue, this condition silently erodes cognitive function, emotional regulation, and physical stability. Modern fires, fueled by plastics, synthetics, building materials, vehicles, and batteries, release a toxic brew of gases, heavy metals, and particulates. Among these, carbon monoxide remains the most underestimated threat.

CO binds to hemoglobin more than 200 times stronger than oxygen. Even small exposures can deprive the brain of oxygen long enough to trigger acute injury. But for many, the greater danger comes later. Delayed Neurological Sequelae (DNS)—a progressive neurological decline occurring weeks or months after exposure—often goes unrecognized, untested, and untreated.

This is the unseen battlefield Marissa Halbeisen, a veteran firefighter, stepped into after a wildfire response that changed her life. Her story is not an outlier—it is a warning.

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The Night Everything Changed

Marissa had survived two decades of fires, rescues, and high-risk deployments. But in January, during a wind-driven Los Angeles wildfire, she encountered a hazard she couldn’t see. Working through hurricane-force winds, sandblasted eyes, and suffocating smoke, she made a choice many engineers make on wildfire operations: she saved the limited air supply for the nozzle teams. She stayed in the smoke.

“It wasn’t the flames that nearly took me out... the smoke I couldn’t see almost did.”

By the time the fire crossed the highway, her head was pounding, her vision blurred, and her breathing felt labored. She assumed it was exhaustion—an unavoidable part of the job. She didn’t know the true injury was already unfolding inside her brain.

 

The Descent Into the Invisible Injury

In the weeks that followed, Marissa began experiencing symptoms that alarmed her: mental fog, slowed processing, and memory problems. Tasks she once performed effortlessly suddenly felt foreign. Teaching at the fire academy became difficult. Studying for her captain’s exam—material she knew cold—was impossibly hard. “I looked fine on the outside. Inside, it felt like someone unplugged my brain.”

By April, her once-rigorous workouts stopped. By May, she pulled herself off duty—a decision firefighters rarely make without extreme cause. She underwent blood tests, autoimmune panels, imaging, and routine assessments. Everything came back “normal.”

But nothing was normal.  She developed overwhelming fatigue, full-body aches, slurred speech, and balance problems. At her worst, she could not drive. “It felt like being intoxicated all the time without having touched a drink,” she said.

An ER visit revealed nothing on standard tests. Yet deeper investigation finally uncovered the truth: hypoxic brain injury linked to CO exposure. MRI imaging, a toxicology assessment, and evaluations by occupational medicine specialists revealed she had experienced significant carbon monoxide poisoning—followed by delayed neurological decline.

She was left with the classic signs of DNS: cognitive impairment, motor coordination issues, hormonal disruption, and chronic neuroinflammation.

The System Misses What It Cannot See

Marissa’s ordeal highlights a troubling reality: CO injuries are wildly underdiagnosed, especially among firefighters. Wildland operations, unlike structure fires, often lack formal rehab protocols or CO monitoring. Firefighters frequently operate in heavy smoke without SCBA, believing the risk is acceptable or temporary. The consequences can be catastrophic. Research shows that mild to moderate CO exposure can trigger:

• Memory loss and slowed processing

• Personality changes and irritability

• Balance and gait disturbances

• Hormonal dysregulation

• Autonomic nervous system impairment

• Increased risk for long-term neurodegenerative disease

Yet because CO clears from the blood within hours, by the time a firefighter seeks help, measurable evidence has vanished. Only MRI, neurocognitive testing, and clinical experience reveal what the bloodstream no longer does. “They told me my tests were normal. My body was telling me I was drowning.”

Marissa’s experience reflects the silent epidemic affecting many firefighters, veterans, athletes, and civilians exposed to toxic air.

 

Finding a New Model of Care

When traditional medicine failed to explain her symptoms, Marissa found a different path through Dr. Leslie Valle-Montoya and the Brainwave Wellness Institute—an organization dedicated to non-invasive brain performance therapies and recovery from toxic exposures.

Dr. Valle-Montoya conducted deeper diagnostic testing, including mineral and heavy metal screening, autonomic assessments, and inflammatory mapping. The results confirmed what Marissa felt: her body was carrying a toxic burden, and her nervous system was in distress.

Treatment included:

• Mild hyperbaric therapy to improve oxygenation

• Ozone nebulization to clear the mucus membranes damaged by smoke

• Bioenergetic frequency therapy to support detox and brain recovery

• Niacin-assisted sauna detoxification

• Nutrition protocols and hormone-balancing strategies

Within weeks, Marissa noticed sparks of improvement. Her clarity brightened. Her energy rose. She still faced challenges—but now she finally had a plan.

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A Broader Crisis: Many Suffer in Silence

Marissa’s story echoes across the fire service. For every firefighter diagnosed, many more quietly struggle. Symptoms like irritability, “forgetfulness,” trouble concentrating, unexplained fatigue, or emotional volatility are often written off as stress. Departments lack consistent monitoring, education, or long-term tracking of neurological symptoms.

The truth is stark: CO poisoning and neurotoxic smoke exposure may be one of the most overlooked occupational diseases of modern firefighting. Organizations such as the Brain Injury Alliance, Carbon Monoxide Safety groups, IAFF wellness programs, and emerging CO survivor networks are beginning to push awareness forward. But most sufferers still remain undiagnosed—soldiers in a silent war against toxins that do not show up on standard lab panels.

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Marissa’s Mission: Turning Injury Into Advocacy

Despite ongoing recovery, Marissa’s spirit remains anchored in service. She refuses to let this invisible injury silence her. Instead, it has sharpened her purpose. “If I make it back, I’m coming back better than before—and I’m taking others with me.”

She now hopes to educate firefighters on early detection, advocate for CO monitoring protocols, and support national organizations fighting for recognition of toxic exposure injuries. Her story represents both a warning and a roadmap—proof that invisible injuries are no less devastating, and no less deserving of care.

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A Call to Action

Marissa’s experience makes one thing clear: the fire service must evolve.

• CO monitoring must become standard.

• Rehab must be mandatory on wildland incidents.

• Neurological screening must be built into occupational health.

• Firefighters must be taught to recognize—not hide—signs of cognitive decline.

For every Marissa who speaks out, dozens remain unheard. This newsletter—and this story—is for them.

Because the smoke may clear from the hillside, but for many, it lingers in the brain long after the fire is gone.