Can I Sleep In A Car With Windows Rolled Up?

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Embarking on a long-distance adventure means you may spend a night or more in the car before arriving at the destination. Also, during camping, many people prefer to sleep in their cars, but how safe is that? Especially when the car windows are rolled up.

Different situations can prompt someone to ask, “can I sleep in a car with windows rolled up?” the reason why people capitalize on rolling up car windows while they sleep is to ascertain their safety and security.

However, while it is generally safe to sleep in a car with windows rolled up, there are factors that can change this stereotype answer and make it generally unsafe to sleep in a car with closed windows.

Can I Sleep In A Car With Windows Rolled Up?

There are factors to consider before sleeping in your car with closed windows. These factors are not limited to weather, season, the type of car you drive, and how long you wish to sleep inside the car. We are going to pick these factors individually and explain all of them.

Cars Are Not Airtight

For something to be airtight, it means that there’s no possible way for air to penetrate it. But cars are not airtight. Even though automakers are working to make cars as airtight as possible, natural air can still flow into cars.

However, not as much as you may think. A compact vehicle or sedan holds up to 3,000-4,000 liters of air. Hence, oxygen will always flow in the car.

More so, cars have ventilation systems and little spaces where air could penetrate from. For example, if you turn off your car AC and roll up the windows while you drive past a burn, after a while, you’ll begin to scent the burnt stink in your car; how did it get in?

Apparently, it went through the various porous corners of your car to get inside. This is clear proof that cars are not airtight.

So, when you sleep in a car, even with the windows rolled up, air (oxygen) can still penetrate.

Is Your Engine On/Off?

Cars Are Not Airtight

From various perspectives, it is not safe to sleep in a car when the engine is still on. You may want to ask why?

When the windows are all rolled up, and fresh air is literally blocked from penetrating the car, with the engine still one, fumes from the exhaust pipe can possibly get into the car and mix with the limited air in circulation – this is very dangerous to one’s health.

The contaminated air now contains carbon monoxide, a colorless, odorless gas that can cause fatigue and serious damage to your body systems.

In essence, when your car engine is on, it is very unsafe to sleep inside that vehicle with closed windows. It would be better if you simply turn off the engine and get yourself a good rest before continuing with the journey.

“Besides, many truck drivers frequently sleep in their cars for as long as possible, and this has become a norm for them.”

A handy tip: when it’s obvious you need to get a nap before continuing your journey, turn off the car, roll down the window for like 10 minutes to introduce more fresh air into the vehicle.

Then roll back the windows up (with the engine still OFF), ensure the car is locked, and you can enjoy some sleep. If you don’t lock your car, anyone could open it and gain access to your important stuff.

Park at an Open Space

Where to park is the biggest challenge when it comes to sleeping your car. Parking in an open air space is okay, but is the area safe and secure? It’s also okay to park under a tree or a shelter to avoid severe heat from the sun.

However, if the area you park isn’t safe, thieves and hoodlums can break into your car forcefully while you sleep and even get you injured while robbing you of your valuables.

Personal protection is the foremost thing to think about. You can park in a police station, hospital, or any safe parking lot to get some rest.

When an officer or a guard approaches you to understand why you parked in their premises, simply tell the guard that you need to rest your eye before continuing – many of them will understand.


For someone asking, “can I sleep in a car with windows rolled up?” the simple answer is yes. But you should consider your safety by parking in a secure environment and ensure that your car engine is OFF.

Also, before the sleep, open up the windows for some minutes to allow some good fresh air in before rolling them up to rest.

However, if you’re traveling with passengers on board, while all these tips apply, you should also consider cracking a window for more proper circulation.

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