Should You Turn Your Car Off While Sleeping?

Sometimes sleeping in your car is unavoidable. However, if you have to do it, it’s important that you know how to do it safely. For example, do you know whether or not you should turn off your car while sleeping?

You should always turn off your car while sleeping in it. Leaving it running while you sleep is not a good idea because it can lead to carbon monoxide poisoning, which can be fatal. Furthermore, letting your car idle for too long can waste gas, overheat its engine, and hurt the environment.

The rest of this article will discuss more topics related to this question, including why you should turn your car off while sleeping and how to safely sleep in your vehicle when needed.

Why You Should Turn Your Car Off While Sleeping

As I mentioned before, you should never leave your car on while you’re sleeping inside it, as this can lead to carbon monoxide poisoning.

Carbon monoxide is odorless and colorless that can poison you without you even knowing. It is a by-product of burning natural gas or other materials containing carbon. Whenever your car uses fuel, it produces carbon monoxide.

If you leave your car running while you sleep, you run the risk of the carbon monoxide that your car expels finding its way into the cabin of your vehicle. If that happens, it will poison you.

You also shouldn’t leave your car running in your garage for this same reason. Carbon monoxide from a vehicle left running in your garage can seep into your home in no time at all.

According to research done by Iowa State University, this can happen so quickly that a person can collapse before realizing anything is wrong.

Carbon Monoxide is more likely to occur if your car’s mechanical systems are not in the best shape or if it has an exhaust leak. Though, according to UAE Health, carbon monoxide can still build up in your car even with well-functioning systems.

Personal tips: As always, there isn’t one right answer but you should rather adapt to your own situation.
One thing you should always respect is to turn off your engine while your sleeping if you’re in a closed area where Carbon Monoxide could build up and poison you.
In contrary, if you’re outdoor and need to let the engine running because it’s freezing outside, don’t hesitate to do it. More info about sleeping with your engine off here.

Other Reasons To Turn Your Car Off While Sleeping

Apart from the risk of carbon monoxide poisoning, leaving your car on while you sleep is just not a good idea.

For one, it wastes gas. The South Carolina Department of Health and Environmental Control states that leaving your car running for an hour can waste up to half a gallon (1.89 liter) of gas. In the long run, this could waste a considerable amount of money.

Leaving your car on for long periods can also cause your engine to overheat. According to Auto Care Aids, because the outside air and the car’s fans don’t work to cool down your engine when your vehicle is in park, it could overheat if left running for too long. 

On top of all that, idling is known to cause notable damage to the environment. According to the U.S. Department of Energy, the CO2 emissions generated by idling personal vehicles adds up to around 30 million tons annually. 

Considering how many cars are in the U.S., that’s a lot of CO2– a greenhouse gas— going into the environment from just idling alone.

Thus, turning your car off while you sleep will save gas, your engine, and do a little to protect the environment as well.

Related Articles:
Is It Safe To Sleep in Your Car in the Winter?
Can You Sleep in Your Car in National Parks?
How To Sleep in a Car Without the Alarm Going Off
How To Sleep Comfortably in the Front Seat of a Car

How To Be Safe When Sleeping in Your Car

When sleeping in your car, make safety a number one priority. Here are some tips for sleeping in your car:

  • Turn your car off completely. For all the above-stated reasons, leaving your car on when parked is just a bad idea.
  • If it’s warm, park your car in the shade. You can also crack a few windows or use a portable fan. Don’t open your windows all the way, however, as this might encourage thieves. 
ZATOOTO Car Side Window Sun Shades

Fit Metal Surface Window Frame: Easy to install in 5 seconds. Our car side window sunshades will be super firm because we place 16 pieces of small magnets (others sellers 6 pieces) in each window.

If you make a purchase, you support by allowing us to earn an affiliate commission (no added cost for you).
  • If the sun is still bright, use some sun shades. Sunshades will block out any sun and deter people from looking in on you. These Zatooto Car Side Window Sun Shades from are affordable, easy to install, and are great for privacy as well.
  • For the cold, use a sleeping bag. There are sleeping bags specifically designed for cold weather if you need something more heavy-duty. For cool weather, a regular sleeping bag or some blankets should work just fine.
Onirii Inflatable Car Air Mattress

Only 2.5 KG weight, Can be folding, Easy to carry. This package includes 1 air bed,2 air pillows,1 air pump,1 air foot Piers,1 soft travel neck Inflatable pillow,1 sleep mask,2 sleep earplugs,1 repair pad.

If you make a purchase, you support by allowing us to earn an affiliate commission (no added cost for you).
  • Consider investing in a specialized car mattress. If you sleep in your car often, a car mattress could make an excellent investment. This Onirii Inflatable Car Air Mattress from is specially designed to fit snugly in the backseat of your vehicle. It is affordable and makes for a comfortable bed even in such an awkward space.
  • Make sure it is legal. Some states have made sleeping in cars illegal. There are also certain places where it may be prohibited. Make sure that there are no parking restrictions or charges where you decide to stop.
Kidde Carbon Monoxide Detector

CO detector with alert modes & LED lights that pulse for power, CO detection, & low battery.

If you make a purchase, you support by allowing us to earn an affiliate commission (no added cost for you).
  • Buy a carbon monoxide detector. A carbon monoxide detector is a small investment that can potentially save your life. Putting them in your car and home is highly recommended. If you need to leave your vehicle on for more than a minute or so, consider using this Kidde Carbon Monoxide Detector from It is easy to use, battery-charged, and inexpensive.
  • Ensure your car is working correctly. If you absolutely must idle your vehicle for some time– for example, to warm it up if it is freezing– check that your car is in good shape. If your car has mechanical issues, there is a greater chance of CO2 poisoning or vehicle damage. Check that there are no exhaust leaks or blockages in the tailpipe.

Final Thoughts

Always turn your car off while you are sleeping. Idling your car in an enclosed space or when you are inside it could turn fatal due to CO2 poisoning.

If you need to sleep in your car, make sure you are as safe as possible. Check that it is legal to sleep where you are, and take measures to be comfortable.

It is always best to turn your car off when parked anywhere for more than a minute or so. Idling your vehicle can be dangerous, bad for your engine, and damaging to the environment.

Leave a Comment