San Joaquin Valley air officials are telling residents in San Joaquin, Stanislaus, Modesto, Merced, Fresno, Kings, and Kern counties what to do about the smoke, and the South San Joaquin County Fire Authority has not answered press questions about containment.
San Joaquin Valley air officials have issued an air alert for a sprawling medical-supply warehouse fire in Tracy, and they are telling residents across the Central Valley what to do about the smoke: stay inside, limit exertion, watch for symptoms, and, if you are near the plume, go to an emergency room. The fire at a 1-million-square-foot Medline Industries distribution center in Tracy ignited just before 1 p.m. PT on Thursday, and the San Joaquin Valley Air Pollution Control District said smoke is forecast to reach Modesto, Merced, Fresno, and Kings counties overnight and Kern County by midday Friday, on top of the San Joaquin and Stanislaus counties already in the drift path on Thursday.
What is burning is not a typical big-box inventory. The Tracy campus distributed latex gloves, masks, and surgical instruments and served as a key COVID-era medical supply node, according to the Associated Press. That matters because a plastic-and-latex fire produces a different inhalation hazard than a vegetation fire, and the people downwind are not breathing generic wildfire smoke.
San Joaquin County Public Health Officer Maggie Park told the Stockton Record that the plume contains "respiratory irritants, toxic gases, carcinogens and at least one neurotoxin." She advised anyone experiencing sudden respiratory symptoms, headaches, dizziness, nausea, or throat irritation near the smoke to seek emergency-room evaluation. The air district's standing guidance for sensitive groups, including children, older adults, people with heart or lung disease, and pregnant people, is to remain indoors, run air filtration if available, and avoid outdoor exercise while the alert is in effect.
As of 9 a.m. ET Friday, Tracy police said the fire was still active, with reports indicating the facility was destroyed. Fire Chief Randall Bradley of the South San Joaquin County Fire Authority said Thursday's suppression efforts were hindered; the full reason was truncated in the wire copy. The cause of the fire remains unknown, and investigators have not spoken publicly. The South San Joaquin County Fire Authority did not respond to a press inquiry before publication.
The APCD's Tracy warehouse fire update is the operational document to watch: it lists the counties in the projected drift path, the overnight hours when temperatures drop and inversions trap particulates at street level, and the threshold for lifting the air alert. Until then, the public-health instruction is simple and unusually specific for an active industrial fire: treat the air as compromised, watch your own symptoms, and take the children, the elderly, and anyone with a heart or lung condition indoors before the wind shifts again.
That instruction carries a separate complication. Medline's Tracy campus is one of the country's largest single-site medical distribution facilities, and the loss of its inventory, even temporarily, will ripple through hospital and clinic supply chains. That is a story to verify against Medline's own statements and federal supply-chain data; it is not something the public-health alert is asking residents to act on tonight. Tonight's alert is asking them to act on their own lungs.