How Long Can You Sleep in a Closed Car?
2 Answers
It is generally not recommended to sleep in a sealed car for more than 3 hours. The duration of sleeping in a sealed car should not be too long, as the lack of fresh air circulation can lead to an increase in carbon dioxide concentration inside the vehicle, thereby increasing the risk of suffocation. Under normal circumstances, staying in a sealed car for more than 3 hours can cause discomfort symptoms such as abnormal heart rate and difficulty breathing. Therefore, it is advised not to sleep in a sealed car for more than 3 hours. Below are some hazards of sleeping in a car: 1. Limited Space: The confined space in a car can easily lead to muscle fatigue and neck stiffness. 2. Closed Doors: With the doors closed, there is a risk of oxygen deprivation and carbon monoxide poisoning. High temperatures can accelerate oxygen deprivation. 3. Vehicle Windows and Doors: With advancements in technology, modern vehicle windows and doors have excellent sealing properties, making the small interior space poorly ventilated. In cold and dry winters, resting with the heater on in a stationary car or in a poorly ventilated garage can lead to oxygen deprivation or even shock symptoms if the rest period is prolonged.
Last time I tried overnight camping in the car, personal experience proved this requires extra caution. The biggest risk of sleeping in a car is carbon monoxide buildup—even when turned off, interior materials slowly release harmful gases. Summer is more dangerous as the cabin becomes like a steamer, risking heatstroke within twenty minutes; winter poses carbon monoxide poisoning risks. A fully sealed conventional gasoline car can last at most one hour—it's best to leave windows slightly cracked. Newer electric vehicles with camping mode fare better by automatically ventilating, but still shouldn't exceed eight hours. For proper car rest, recommend using external air circulation plus sunroof gaps, and regularly checking physical condition.
