Los Angeles, CA – Winter officially begins today as California marks the Winter Solstice, the shortest day and longest night of the year. While California is often associated with mild weather, safety officials warn that the longest night of the year still brings increased risks inside homes—particularly from carbon monoxide exposure during cold snaps, storms, and power outages.
Across California, winter conditions vary widely. Northern California and mountain regions often experience freezing temperatures, snow, and extended storms, while Southern California sees cooler overnight lows that prompt increased use of heaters and fireplaces. Space heaters, gas heaters, wood-burning fireplaces, and backup generators are commonly used during colder nights. With windows closed and ventilation reduced, carbon monoxide can accumulate indoors.
Carbon monoxide is a colorless, odorless gas produced when fuel-burning appliances do not burn completely or are not properly vented. Because it cannot be seen or smelled, it is widely known as the “invisible killer.” According to the Centers for Disease Control and Prevention, carbon monoxide poisoning sends tens of thousands of Americans to emergency rooms each year, with winter months posing the highest risk—even in states with generally mild climates like California.
Medical experts warn that carbon monoxide poisoning disables far more people than it kills, often leaving survivors with long-term neurological or cognitive damage. Early symptoms may include headaches, dizziness, nausea, fatigue, and confusion. As exposure continues, symptoms can escalate to chest pain, vomiting, impaired coordination, loss of consciousness, and death. Because these symptoms often resemble flu-like illness or exhaustion, many people do not recognize the danger until exposure becomes severe.
Fire departments across California caution that carbon monoxide incidents often increase during winter storms and overnight cold periods, including around the Winter Solstice. Common causes include space heaters placed too close to walls or furniture, grills or fuel heaters used indoors or in enclosed patios, generators operated too close to homes during outages, and vehicles left running in garages. In wildfire-prone or mountainous areas, blocked vents and chimneys can further increase risk.
Safety officials urge California residents to ensure carbon monoxide detectors are installed on every level of the home and outside sleeping areas, regardless of how often heating systems are used. Alarms should be tested regularly, and batteries replaced as needed. Residents are also advised never to use grills, camp stoves, or fuel-powered heaters indoors, to operate generators outdoors and far from windows and doors, and to ensure heating systems and fireplaces are properly maintained.
If a carbon monoxide alarm sounds, officials say residents should leave the home immediately and call 911 or the local fire department from outside. Anyone experiencing symptoms of carbon monoxide exposure should seek emergency medical care without delay.
As California experiences the longest night of the year, safety officials say the Winter Solstice is more than a seasonal marker. It is also a reminder that carbon monoxide—the invisible killer—can pose a serious but preventable danger when colder weather and reduced ventilation catch residents off guard.
