Is it safe to sleep in a car? Let's put an end to this mind-boggling question!

Updated Aug 16, 2022 | Same topic: Survive driving in the Philippines

Have you ever slept in your car? Next time you plan and think of sleeping inside the comforts of your car, think again.

For many of us, our car is not only a vehicle that we use to travel to destinations. It is a place where you enjoy your music, a place where you can relax, have fun and at times take rest too. Some of us even take rest by sleeping in car with engine on during a long drive. It has been sort of a habit of most people as well.

Is it safe to sleep in your car? Do you know this can be fatal? What are the possible side effects that may arise to both the driver and the vehicle? We at believe it's about time to put an end to these mind-boggling questions.

1. Dangers of Sleeping In a Car

Studies shows and experts advised that there are certain dangers that may arise from doing a habit of sleeping inside your car. Regardless of what type of vehicle, experts proved that someone could die in suffocation even in less than an hour of sleeping inside your car.

There are several factors that increase the risks of accidents and health problems when sleeping inside a car. The danger is much more evident especially when the features of the car is not adequate or up to par.

There’s a possibility of vehicle breakages or leakage on a car’s exhaust that can reach on the inside of a car which can furthermore increase the risk of suffocation because of the decrease of the presence of oxygen inside the car.

>>> Check out 10 basic car maintenance tips to prevent potential breakages

A man sleeping in car with engine on

Accumulating too much carbon dioxide can cause suffocation and even death

Inhalation of too much Carbon Monoxide from an exhaust leakage which then can result in suffocation. Carbon Monoxide is a harmful substance especially when it reached our bloodstreams. Excessive presence of Carbon Monoxide in the blood can cause shock or worst sudden death. It is a major component in your car's exhaust fumes and if large quantities accumulate in your cabin, you will be in trouble.

The problem with Carbon Monoxide is it is an odorless, tasteless and colorless, gas and hence you will not even realize you are breathing in poison. Carbon monoxide can also cause temporary dizziness, shortness of breath, etc if you sleep in your car with windows up for lesser than an hour.

Some believe that sleeping in car with engine on is already safe if the car has a well-functioning air condition system. Well but even so, the air is enclosed in a suppressed area which still can lead to the production of more carbon monoxide and less oxygen.

2. Is it safe to sleep in your car if the windows are open?

Another common misconception is that whether it is safe to sleep in your car with at least a window rolled down. Even with a window open, it is still not enough to produce a sufficient amount of oxygen and can cause a person to lose body fluids and water.

>>> Also read: 10 tips you need to follow to avoid sleepiness while driving

is it safe to sleep in your car with window open?

A small opening on the window does not provide sufficient airflow so there's still more danger than safety

3. Difference between driving long hours and sleeping in a car

Another question may arise from this topic. What’s the difference of driving for long hours or sleeping on your car in the same manner?

The difference is when you are awake, you are conscious and aware if ever there is leakage or if there’s something going on inside your vehicle. You are much more aware if the temperature is getting high or low compared to when you are soundly asleep.

If you are sleeping, you are unaware of what’s going on in your surroundings. You are much more unaware of whether the temperature is rising which can furthermore accumulate carbon monoxide build up. 

a man sleeping in car with engine on and window up

When you're asleep, you're not aware of what's going on in your surroundings

4. Avoid sleeping inside cars at all cost

Doctors have advised drivers to sleep in the car only when it’s an emergency, and even when you’re awake you should always take short breaks by getting out of the car when driving for long periods of time

So in case of emergency, how to sleep in your car safely?


Have regular checkups for your auto

It’s essential to have your vehicle’s air condition system be checked from time to time preferably every six months. In order for you to check if there’s a possibility of leakage, you should have it checked every once in a while. Air-condition leakage can cause your vehicle to not cool properly or may take longer than usual to start cooling.

If an air condition system keeps on breaking down or is not working properly, it may cause the temperature to increase up to twice as high as usual. Sleeping in your car with engine on won’t just have harmful effects to your health but to your car as well. Having the engine running while in an idle position is generally frowned upon by automotive enthusiasts.

The primary reason for this is that it isn't the most efficient engine speed for most engines. It can also cause your fuel to be left burning and may result in a car’s unwanted wear. The additional wear on all associated moving parts means that you'll need to get them serviced or repaired that much sooner than when you normally do car maintenance.

car airconditioning

Have your auto's A/C be checked every 6 months.

Keep your car clean

You should often clean your car to ensure your comfort and also your health. Having the engine running while sleeping can also introduce and promote additional pollutants to your immediate area; pollutants that you yourself may be breathing in and inhaling in since you’re sleeping inside your car.

Also, this can cause malfunction to a car’s battery. A car’s battery typically lasts from 18 to 36 months with proper care. But due to having it running while in a stationary motion, may last lesser than usual.

5. Is it safe to sleep in a car? Final Thoughts

Having a car is both a privilege and a responsibility. It will surely take you to good places and create tons of adventures and memories with it but using it beyond its primary function may cause hazard or danger. It is as well our responsibility to fully be aware and be well-educated of the possible side effects of the things we do and decisions we make especially if it’s life-threatening.

I hope we are finally able to put an end to speculations whether or not it’s safe to sleep in your car or not. So the next time you plan and think of sleeping inside the comforts of your car think again.  

>>> Click to get more helpful tips for safe driving

Hanna Sanchez

Hanna Sanchez


Hanna is one of the most competitive swimmers in the country during her day. It was not long before she discovered her passion for the automotive industry as well. Nowadays, she balances her passion through writing as well as coaching.

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