Is it safe to sleep in a car with the air conditioning on in summer?
4 Answers
It is not safe to sleep in a car with the air conditioning on in summer, as it may lead to carbon monoxide poisoning, which is extremely dangerous. It is advised not to do so. The car air conditioning is an important comfort feature in a vehicle, capable of both cooling and heating. When cooling, the AC button needs to be pressed, which engages the compressor clutch, allowing the engine to drive the compressor. The compressor then continuously compresses the refrigerant and delivers it to the evaporator. The car air conditioning system can cool, heat, ventilate, and purify the air inside the cabin, providing a comfortable environment for passengers, reducing driver fatigue, and enhancing driving safety.
Sleeping in the car with the AC on during summer may sound comfortable, but I must warn you it's not a safe choice. After years of driving, I've witnessed too many tragic cases: idling engines emit carbon monoxide, which rapidly accumulates in a closed vehicle and can cause dizziness, unconsciousness, or even death – especially in sweltering weather. Other risks include engine overheating damage and battery drain. Even with the AC running, closed windows prevent air circulation, and rising CO2 levels can make breathing difficult. If you must rest, park in a ventilated, shaded area, crack the windows slightly, and set an alarm to limit sleep duration. Ideally, avoid prolonged stays in the car – safety far outweighs temporary comfort.
From a health perspective, sleeping in a car with the air conditioning on is quite unfriendly to the body. The AC dries out the air, affecting respiration and skin health; coupled with the small interior space, carbon dioxide builds up quickly, making people drowsy and leading to poor sleep quality. Even more dangerous is the emission of carbon monoxide during idling—it's colorless, odorless, but highly lethal. I once experienced nearly dozing off in the car due to fatigue during summer driving, but after learning about these risks, I no longer dare to take the chance. It's advisable to open windows for ventilation in hot weather or take short breaks after turning off the engine—don't use the car as a bedroom. Health comes first; choosing a cool indoor spot is a better option.
As someone who frequently drives long distances, I have to admit that taking a nap in the car with the AC on is tempting, but there are ways to make it less risky. For example, park in an open and well-ventilated area, roll down the windows by one-third to allow air circulation; don't idle for too long, set a 30-minute alarm to prevent oversleeping. I've tried it a few times, but stopped after learning about the dangers of carbon monoxide. Short breaks are fine, but prolonged sleep is not advisable. For safety, it's better to get out and stretch or rest under a tree. Don't be careless.
