Sleeping in your car with the AC on and the engine running could be deadly. Picture for illustrative purposes only. Image Credit: Francois Nel/Gulf News

The idea of parking your car and taking a long nap or a quick siesta during your lunch break is a regular habit for many people.

But with medical experts strongly advising against it, Dubai Police are warning the public about the dangers of sleeping in your car.

Regardless of the car being old or new, experts at the General Administration for Criminal Security at Dubai Police said that in less than an hour one could die due to suffocation.

Dr Babu Shershad from the First Medical Centre in Dubai told Gulf News that there are several factors that increase the risks of accidents and health problems when sleeping in a car.

If the mechanical features of the car are not up to par, the possibility of a leakage of the car’s exhaust into the vehicle’s cabin while a person is sleeping can further increase the risk of suffocation as it would lower the oxygen level inside the car, said Dr Shershad.

“The main thing to watch out for is carbon monoxide (CO) accumulation which can be caused by a leak from the exhaust,” he added.

Shershad noted that while CO is poisonous to the blood, an increase in CO levels in a car compromises the amount of O2 reaching the blood. This results in the blood carrying more CO which can lead to a shock or in severe cases sudden death.

Even in the case of a car with a well-functioning AC system, the air circulation in a closed space can be compromised.

“Breathing air in a closed space even if the air circulates in and out of the car is not enough,” said DrShershad. He also pointed out that some of the air gets trapped in the circulation process therefore increasing the level of carbon monoxide and decreasing the level of oxygen.

Besides a functioning AC, another common misconception among many is the idea that an open window will create a sufficient ventilation system in the car.

“Even with the window open, CO will accumulate at a lower level eventually lowering the oxygen in the blood and causing the person to lose body fluids and water after a period of time,” said Dr Shershad.

The doctor also compared the body’s loss of fluids to a simple experiment of timing how long a wet cloth takes to dry in a car.

Asleep or awake, what’s the difference?

While many wonder about the difference between driving for hours with the AC on or the window rolled down and sleeping in the same conditions, Dr Shershad solves the mystery.

“When you’re driving for long periods of time, you are aware of the temperature in the car as well as any possible leaks,” he said.

People usually roll down their windows if the air inside the car starts to feel stuffy or if they’re in need of some fresh air, he added.

However, in the case of sleeping inside a car, a person is unaware of the temperature levels and therefore can be susceptible to heat build-up and CO accumulation.

“I recommend drivers to take short breaks by getting out of the car when driving for long distances,” said Dr Shershad. He also urged people to avoid sleeping in their cars unless it is an emergency.

Checking your AC

Zubair Sharif, a service advisor at Max garage, recommends people to check their car’s AC every six months.

He also said that one should get the AC’s evaporator and piping from the engine checked for possible leakages.

“If the AC is leaking, it might not cool properly or take a longer time to start cooling causing the system to start and stop again at random,” he added.

The possibility of the air-conditioner breaking down or not working as well after a period of time can cause the temperature to spike up to two or three times the ambient temperature, said Dr Shershad.

“The ambient temperature is one where a person is comfortable in carrying out normal tasks in his car, which is around 20 degrees,” said Dr Shershad adding that in such a case the temperature can rise to around 60 degrees. Whether it is a cool or hot day, the outside weather is said to have no significant effect on the inside temperature of a car.