Is It Safe to Sleep in a Car with the Air Conditioning On in Summer?
3 Answers
Sleeping in a car with the air conditioning on in summer is not safe. According to experimental data, in a closed car, running the air conditioning produces a large amount of carbon monoxide. In just over 20 minutes, the carbon monoxide concentration can exceed safe levels significantly, causing a noticeable sense of suffocation. Regardless of the type of car or whether the air circulation is set to internal or external, carbon monoxide can still enter the cabin. Precautions for using air conditioning: 1. Use external circulation after sun exposure: If the car has been exposed to the sun outdoors, first turn on the external circulation to ventilate and dissipate heat. Additionally, opening the windows and sunroof can speed up heat dissipation. After 3-5 minutes, when the interior temperature has stabilized, close the windows, turn on the cooling, and switch the air circulation to internal. 2. Use internal circulation in cold weather: In cold weather, wait a moment after getting in the car until the engine reaches normal operating temperature. Then, turning on the heater with internal circulation can quickly raise the temperature. 3. Use external circulation on highways: During high-speed driving, you can turn on the external circulation as needed. Prolonged use of internal circulation during long drives can lead to stale air inside the car, so switching to external circulation helps maintain a comfortable temperature while bringing in fresh air. However, if the air conditioning was initially turned on to cool the car, avoid keeping the external circulation on continuously. Instead, periodically switch to external circulation to refresh the air.
I was really shocked by a news report I saw last time - someone fell asleep in their car with the AC on during summer and never woke up. The main issue is that when a car idles in place, exhaust fumes from the tailpipe can seep into the cabin through trunk gaps or window cracks. That stuff is called carbon monoxide - a colorless, odorless killer gas! There was even a case last year involving a newly modified car with sealed strips. If you must rest in your car, remember to crack open a window slightly, and it's best not to exceed 20 minutes. Oh, and don't park with your front end facing a wall - the exhaust can bounce back making it even more dangerous. Just thinking about it now gives me chills down my spine - seriously, don't gamble with your life.
As a veteran driver with twenty years of long-distance experience, I must say this habit is extremely dangerous. Prolonged engine idling not only wastes fuel but also produces large amounts of carbon monoxide. Last year, a young guy in our fleet was taking a nap in the service area with the air conditioning on. Luckily, I knocked on the window and woke him up—his lips were already turning purple. Modern cars have increasingly better sealing, making them seem comfortable but actually dangerous. If you really need to rest, find a shady spot and sleep with the windows open. Running the air conditioning not only drains the battery but could also leave you stranded. We long-haul drivers always carry foldable lounge chairs—sleeping under a tree is much safer than inside a metal box.
