Is it okay to sleep in the car in winter without opening the windows?
6 Answers
If the air conditioning is not turned on, it is acceptable to sleep for a short period without opening the windows. However, for prolonged sleep, it is recommended to open the windows. Sleeping in the car with the air conditioning on is not advisable. Below are some relevant points about sleeping in the car during winter: 1. Duration of sleeping in a sealed car in winter: Generally, it is not recommended to exceed 3 hours. 2. Precautions for prolonged sleep in the car during winter: Leave a gap in the window. When sleeping in the car, it is essential to leave a small gap in the window because the confined space has limited air supply; Activate the car's air recirculation mode. Cars typically have three modes: internal, external, and mixed. Most drivers tend to use the internal mode when resting to retain warmth, but it is generally advised to use the mixed mode, as the internal mode alone does not ensure proper air circulation.
As a long-term vehicle maintenance technician, I strongly advise against sleeping in a car with the windows closed during winter. This isn't just about comfort—when the engine is running with windows shut, exhaust fumes can seep into the vehicle and accumulate carbon monoxide (CO), which is colorless and odorless but can be fatal within minutes. I've had cases where clients nearly died from poisoning during short naps. Even with the engine off, prolonged time in an enclosed space causes carbon dioxide levels to rise, leading to oxygen deprivation and breathing difficulties that can trigger accidents. While modern vehicles have ventilation systems, they aren't reliable enough; you must crack a window slightly to ensure fresh air circulation. Safety should always come first—never prioritize warmth over risk.
As someone who has been concerned about public health for years, this behavior poses extremely high risks. Keeping windows closed during sleep prevents air circulation, leading to CO2 buildup that can cause dizziness and headaches. If you start the engine for warmth, CO poisoning becomes a common hazard that may result in permanent damage. Children and the elderly, with their weaker constitutions, are even more vulnerable. It is recommended to turn off the engine when resting in the car, crack a window slightly for ventilation, or use portable heating sources for warmth. Health should never be taken lightly—always prioritize well-ventilated parking spots for safety.
Personal experience: Once, feeling exhausted during a trip, I took a nap in the car with the windows closed. Upon waking up, I had difficulty breathing and felt suffocated. The engine wasn't running, but the oxygen was dangerously low, which terrified me. Since then, no matter how cold it is, I always crack open the sunroof a bit when parked to let in some cold air. Ventilation is a lifeline—never take chances.
As parents, we find this extremely dangerous. Children's fragile bodies are at high risk—once CO poisoning occurs, there may be no time to call for help. Sleeping in a car with closed windows creates an enclosed environment, multiplying the risks. Educate your family: always turn off the engine and leave windows slightly open for ventilation—never skip this step. Use blankets or sleeping bags for warmth instead. Family safety is no trivial matter—prevention comes first.
Hey, tried sleeping in the car with windows closed in winter and regretted it. Woke up feeling stuffy, with a headache and nearly fainted. If you turn on the heater, CO might silently poison you. It's safer to park, turn off the engine, and crack a window slightly while using thick clothes for warmth. Safety first—don't follow my example.
