How many hours can you sleep without opening the car window?
2 Answers
It is not safe to sleep in a car without opening the windows. Risk of carbon monoxide poisoning: In a closed car, the air circulates internally through the air conditioning, causing the carbon monoxide concentration to rise. At the same time, passengers exhale large amounts of carbon dioxide, leading to a rapid decrease in oxygen levels. Within hours, this can cause nausea, unconsciousness, and in severe cases, suffocation or death. Avoid sleeping in the car with the heater on: Similar to the principle of using the air conditioner, the engine produces high concentrations of carbon monoxide when fuel does not burn completely. While driving, the air inside the car is exchanged through the air conditioning system, keeping carbon monoxide levels low. However, if the car is stationary with the heater on and windows closed, high levels of carbon monoxide can enter the cabin, making it easy for people sleeping inside to suffer from poisoning or suffocation.
As someone who frequently focuses on automotive safety, I consider sleeping in a car with the windows closed extremely dangerous and strongly advise against attempting it for more than 15 minutes. The enclosed space of a vehicle has poor air circulation, and as a person breathes, they consume oxygen and exhale carbon dioxide, quickly leading to stale air and increased humidity, which can cause dizziness and chest tightness. Even more alarming is that if the engine is left running or external pollutants seep in, carbon monoxide can accumulate to dangerous levels in just a few dozen minutes, leading to suffocation or even death. I have handled similar accident cases where symptoms appeared in as little as 30 minutes. Therefore, I recommend only taking short naps in emergencies, always leaving a window slightly open for ventilation, parking in open areas, and ensuring fresh air can flow in. For safety, it’s best to avoid sleeping in a car altogether and opt for a hotel or tent instead.
