Why is it dangerous to sleep in a car with the air conditioning on?
4 Answers
The reason why it is dangerous to sleep in a car with the air conditioning on is that the relatively sealed environment can easily lead to carbon monoxide poisoning, causing personal accidental injuries. The functions of car air conditioning are: 1. Achieving cooling effects through the continuous cycle of refrigerant; 2. Removing dust, odors, smoke, and toxic gases from the air inside the car, making the air fresher, and humidifying the air to increase relative humidity. Methods for using and maintaining car air conditioning include: 1. Avoid setting the temperature too low; 2. Control the direction of the air vents; 3. Do not use it for extended periods; 4. Appropriately use high fan speeds; 5. Turn off the air conditioning when driving at low speeds.
A few days ago, I was discussing this with my colleagues, and none of them believed that sleeping in a car with the air conditioning on could be dangerous. The reason lies in the carbon monoxide from the exhaust fumes that can silently seep into the cabin, especially when the engine is idling and emitting large amounts of exhaust. If the car is well-sealed or parked in an enclosed space, the gas concentration can rise rapidly. Carbon monoxide is colorless and odorless, making it impossible to detect while asleep. Just a few breaths can lead to poisoning and unconsciousness, and there have been many tragic cases reported in the news. Running the air conditioner only circulates the indoor air, gradually reducing oxygen levels and leading to hypoxia or suffocation. I believe safety is far more important than convenience. When taking a break in the car, it's best to turn off the engine, crack a window for ventilation, or simply step outside to stretch your legs. Developing this habit can be life-saving, especially during long road trips—don't take the risk out of laziness.
I'm very cautious about this danger when taking my child out alone. Sleeping in a car with the air conditioning on in a confined space can easily lead to carbon dioxide buildup. Poor air circulation increases the risk of oxygen deprivation, and both children and adults in a deep sleep may react slowly, making the situation even more dangerous. Although the air conditioning system can cool the air, exhaust fumes from the running engine can enter the cabin, posing a high risk of carbon monoxide poisoning. A similar accident once happened to a neighbor, but thankfully it was discovered early. Temperature fluctuations can also affect comfort, leading to dehydration and chest tightness. I recommend turning off the air conditioning when parked, leaving a window slightly open, or choosing a shaded spot to rest briefly. It's also important to educate family members to avoid this habit—small safety details can prevent major risks.
Back when I was learning to drive, my instructor kept reminding me about this. When idling with the AC on while sleeping, exhaust fumes from the tailpipe can be sucked into the car by the AC, and carbon monoxide builds up alarmingly fast. I remember almost making this mistake on my first road trip—thankfully, a friend stopped me. If you fall asleep and react slowly, the consequences could be dire. Cracking the window for a short time is fine, but sleeping for long periods is absolutely dangerous, especially for beginners who might overlook it. Safety is no small matter—make it a habit to either turn off the engine or open the windows.
