Is It Safe To Sleep In A Car? Risks and Safety Tips

Long drives, road trips and late-night journeys can leave drivers feeling exhausted. In those situations, pulling over for a short rest can be much safer than continuing to drive while tired. But is it actually safe to sleep inside a car?

The answer depends on several factors, including whether the engine is running, the weather outside, ventilation, where the car is parked and what type of vehicle you are using.

In the UAE, extreme heat adds another important risk. Here is everything you need to know before sleeping inside a car.

Is It Safe To Sleep In A Parked Car?

Yes, sleeping inside a parked car can be reasonably safe for a healthy adult if the vehicle is parked in a secure location, the engine is switched off, and the weather is suitable.

However, problems can arise when:

• The engine is left running
• The car is parked in an enclosed area
• Cabin temperatures become too high
• Ventilation is poor
• The exhaust system is faulty
• The vehicle is parked somewhere unsafe or illegal

If tiredness strikes during a long journey, taking a proper break is important. This is especially relevant during longer UAE road trips, where fatigue can build up after several hours behind the wheel. 

Never Sleep In A Car With The Engine Running

The biggest risk when sleeping inside a petrol or diesel car is carbon monoxide poisoning.

Carbon monoxide is a colourless and odourless gas produced by combustion. It can enter the cabin if there is a problem with the exhaust system or if exhaust gases collect around the vehicle.

Possible symptoms include:

• Headache
• Dizziness
• Nausea
• Weakness
• Confusion
• Unusual tiredness
• Shortness of breath

Severe exposure can cause unconsciousness and death. This is particularly dangerous while sleeping because a person may not recognise the symptoms before losing consciousness.

Dubai Police has previously warned motorists against sleeping inside vehicles while the engine is running, particularly because exhaust faults or modifications can allow harmful gases to enter the cabin.

Opening a window slightly is not enough protection against carbon monoxide.

Never Leave The Engine Running In An Enclosed Area

Running an engine inside an enclosed or poorly ventilated space significantly increases the danger.

Avoid sleeping in a running vehicle inside:

• Underground parking areas
• Closed garages
• Workshops
• Warehouses
• Enclosed camping areas
• Poorly ventilated multi-storey car parks

Exhaust gases can accumulate in these spaces even if the vehicle’s windows are partly open.

If you need to stop because of a mechanical problem, follow the correct steps for what to do when your car breaks down on the road rather than remaining in an unsafe location.

Heat Is A Major Risk In The UAE

Even with the engine switched off, sleeping inside a car can become dangerous because of heat.

Cars heat up quickly when parked, particularly during UAE summers. Cabin temperatures can climb well above the outside temperature within a short period.

Research conducted in the UAE has also shown that vehicles can reach dangerous cabin temperatures even when parked in the shade.

Parking under a tree, building or covered parking structure therefore does not automatically make the vehicle safe to sleep in.

Heatstroke can develop when the body can no longer regulate its temperature. Symptoms may include dizziness, headache, confusion, rapid heartbeat, nausea and fainting.

Drivers should take extra precautions when driving during a hot UAE summer. It is also worth checking the cooling system, air-conditioning, battery and tyres before the hottest months. Read our complete guide on how to prepare your car for summer in the UAE.

If temperatures are high enough that the car needs constant air-conditioning to remain comfortable, sleeping inside a petrol or diesel vehicle with its engine running is not a safe solution.

Does Opening The Windows Make Sleeping Safer?

Opening the windows slightly can improve fresh-air circulation when the engine is switched off, and temperatures are mild. However, it does not solve every problem.

A partially open window will not:

• Prevent dangerous cabin temperatures during UAE summers
• Make sleeping with a running engine safe
• Protect against carbon monoxide from a faulty exhaust

In cooler conditions, leaving a small opening can help reduce humidity and stale air inside the cabin.

Can You Run Out Of Oxygen Inside A Car?

A common concern is whether a person can suffocate inside a completely closed car. Modern cars are not airtight. Air can still move through body vents, door seals and ventilation openings.

For a healthy adult sleeping alone in a normally parked car, running out of oxygen is therefore usually not the main risk. However, carbon dioxide levels can increase if several people remain inside a closed cabin for a long period. Fresh-air ventilation can help reduce this build-up.

Are Electric Cars Safer To Sleep In?

Electric cars have a major advantage because they do not produce tailpipe exhaust gases. This removes the carbon monoxide risk associated with running a petrol or diesel engine.

EVs can also operate their air-conditioning while parked without running a combustion engine.

Some models even offer dedicated stationary climate features. Tesla’s Camp Mode, for example, is designed to maintain cabin temperature while the car is parked.

Electric cars are becoming increasingly popular locally. Read our guide to the best electric cars in the UAE to see some of the models currently available.

However, sleeping inside an EV is not completely risk-free. Drivers still need to consider:

• Remaining battery charge
• Outside temperature
• Ventilation
• Parking location
• Security
• Possible climate-control failure

If you use climate control for several hours, make sure the battery has enough charge for the next journey.

What About Hybrid Cars?

Hybrid cars require extra care. A hybrid can appear completely switched off because the petrol engine may stop while the vehicle is stationary.

However, if the vehicle remains in READY mode, the engine can automatically restart to charge the battery or support the air-conditioning.

This means a hybrid should not be treated like a pure electric vehicle. If the combustion engine can start automatically, follow the same exhaust and carbon monoxide precautions.

Children And Pets Should Never Be Left Alone

Children are particularly vulnerable to extreme temperatures because their body temperature can rise faster than an adult’s. Never leave a child unattended inside a parked vehicle, even for a short period. The same applies to pets.

Opening the windows slightly is not enough to stop cabin temperatures from reaching dangerous levels during hot UAE weather. Drivers travelling during summer should also carry adequate drinking water and essential safety items. Here are the top things to keep in your car during summer.

Where Should You Park Before Sleeping?

Location is just as important as vehicle condition.

If you need to stop for a rest, choose:

• A legal parking area
• A well-lit location
• A safe public rest area
• A location away from moving traffic
• An open and well-ventilated place

Avoid sleeping on the motorway hard shoulder unless it is a genuine emergency. You should also avoid blocking entrances, parking on private property without permission or stopping somewhere that creates a danger to other road users. UAE authorities regularly advise tired drivers to stop in a safe place rather than continue driving while drowsy.

Tips For Sleeping Safely In A Car

If you need to take a short rest, follow these basic precautions:

• Switch off a petrol or diesel engine
• Never sleep inside an enclosed garage with the engine running
• Avoid sleeping inside a hot car
• Park legally and away from moving traffic
• Use some fresh-air ventilation in mild weather
• Check that doors can be opened easily
• Keep your phone charged
• Do not leave children or pets unattended
• Avoid parking near another idling vehicle or generator
• Stop using the vehicle immediately if you smell exhaust fumes

What If You Feel Unwell?

If you develop a headache, dizziness, nausea, confusion or unusual weakness while inside a vehicle, leave the car immediately and move into fresh air. Do not remain inside trying to identify the problem.

If carbon monoxide exposure or heatstroke is suspected, seek emergency medical help. In the UAE, the ambulance emergency number is 998.

Is It Safe To Sleep In A Car?

Sleeping in a car can be safe for a short rest when conditions are suitable, but several precautions are essential. The safest setup for a petrol or diesel car is engine off, mild weather, good ventilation and a legal outdoor parking location.

Never rely on a running combustion engine to keep the air-conditioning on while you sleep. In the UAE, high temperatures make sleeping inside an engine-off car particularly risky for much of the year.

EVs with dedicated climate-control or camping features can be a better option, but drivers should still monitor battery level, ventilation and parking conditions. Most importantly, if you are too tired to drive safely, find a secure place to stop and rest before continuing your journey.

Stay tuned to UAE’s most popular auto blog for more information about the latest happenings in all of the Emirates.