Wildfire Smoke and Sensitive Groups: What to Do If You're at Higher Risk

by Amanda Hawkins

Photo by Vitaly Gariev on Unsplash

Wildfire smoke can affect anyone, but some people are at higher risk of symptoms or complications. Recent research has both broadened the list of groups considered sensitive and shown that the health effects of smoke can persist long after the fire is out. If you or someone in your household is in a higher-risk group, it helps to take extra steps before and during smoke events, and to know when leaving for cleaner air may be the best option.

Who Is Considered Sensitive to Wildfire Smoke?

Public health agencies, including the EPA, the NYC Department of Health 2026 Wildfire Season Advisory, and Riverside County Public Health, typically list these groups:

  • Children: Lungs still developing; breathe more air per body weight; often more active outdoors. A 2026 study of pediatric asthma in Northern California found that each 10 µg/m³ increase in wildfire-specific PM2.5 was linked to roughly a 4% same-day increase in asthma hospital visits, rising to about 13% cumulatively over five days, with the largest impacts in already-vulnerable communities.
  • Older adults: More likely to have heart or lung disease and less able to compensate for stress on the body. A 2025 study in JACC linked long-term wildfire smoke exposure to higher rates of heart failure in older U.S. adults, and noted that wildfire PM2.5 appears to have higher cardiovascular toxicity than PM2.5 from other sources.
  • Pregnant people: Smoke exposure can affect both the developing fetus and the pregnant person. EPA guidance cites associations with gestational diabetes, high blood pressure during pregnancy, low birth weight, and preterm birth.
  • People with asthma, COPD, or other lung disease: Smoke can trigger flares and worsen symptoms.
  • People with heart disease, diabetes, or chronic kidney disease: PM2.5 increases strain on the cardiovascular system and raises the risk of events such as heart attack and stroke.
  • People who are immunocompromised: Now flagged in NYC's 2026 wildfire-season advisory alongside the more familiar groups.
  • Outdoor workers, first responders, and unhoused individuals: Riverside County Public Health and others have called out these groups specifically because exposure is harder to avoid.

If you're unsure whether you or a family member is at higher risk, a healthcare provider can help. When smoke is in the forecast or already present, sensitive individuals should reduce exposure more aggressively than the general public.

How Long the Health Effects Can Last

The risks from wildfire smoke aren't limited to the days when the air is visibly smoky. A May 2025 study from Mount Sinai and Harvard, published in Epidemiology, found that elevated risks for cardiorespiratory hospitalizations can persist for up to three months after smoke exposure. The conditions affected included hypertension, ischemic heart disease, stroke, arrhythmia, pneumonia, COPD, and asthma. Hypertension showed the largest increase in hospitalization risk.

For sensitive groups, the practical takeaway is that recovery deserves attention too. Keep up with regular medical care, watch for symptoms in the weeks after a smoke event, and don't assume the danger ends the day the sky clears.

Reduce Exposure: Indoors First

Stay inside with windows and doors closed when smoke is moderate to unhealthy. Create a clean room with filtration so indoor PM2.5 stays as low as possible. See Protect Your Family from Wildfire Smoke: Create a Clean Room. Use central HVAC with a good filter (e.g. MERV 11 to 13) if it doesn't pull in outdoor air, or a portable HEPA air cleaner sized for the room. A DIY box fan filter can help in a pinch.

Know the air before you open up or go out. PurpleAir's map shows real time PM2.5. Use it to decide when it's safe to ventilate briefly or when sensitive family members should avoid going outside.

Limit outdoor activity when AQI is elevated. If someone in the sensitive group must go outside in smoky air, a well-fitting N95 or P100 respirator can reduce how much smoke they breathe. Children should use a size appropriate respirator if recommended by a doctor.

When to Consider Leaving for Cleaner Air

If smoke is persistent and heavy and you can't keep indoor air clean enough (e.g. no filtration, poor sealing, or readings stay unhealthy indoors), relocating temporarily to an area with better air quality or a building with good filtration may be worthwhile, especially for the most vulnerable. That might mean staying with family or friends, or in a hotel or public building with filtered air.

People with severe asthma, COPD, or heart disease should have a plan with their doctor for smoke events, including when to leave, when to seek medical care, and how to ensure an adequate supply of medications. If you or a family member has serious symptoms (e.g. trouble breathing, chest pain, severe cough), seek medical attention.

Plan Ahead

Before fire season, prepare the home (filters, clean room, go kit) and know your options for leaving if needed. See Preparing for Wildfires and When to Evacuate vs. Shelter in Place. For sensitive groups, the same principles apply, with earlier action and lower exposure targets when smoke arrives.

Preparing for Wildfires: Evacuation, Smoke, and Air Quality · When to Evacuate vs. Shelter in Place During Wildfires · Protect Your Family from Wildfire Smoke: Create a Clean Room

Monitor current conditions on the PurpleAir map or with an air quality monitor at home.

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