It is dangerous to sit inside a locked car. It is even more dangerous when the air-conditioning is on. Car exhaust emits carbon dioxide and carbon monoxide gases (in case the AC is on) that might kill an adult instantly. “If you sit inside a locked car for 30 minutes, you would feel suffocated.
You will not run out of oxygen sleeping in a car with the windows closed and the engine turned off. This is because cars are not airtight.
Now an average person requires 6 ltr air per min. So 1500/6 is 250 min. Equals to little more to 4 hours.
If you're going to be sitting in your car for more than 10 seconds, then turn off your engine. If you are sitting near a school, hospital, or heavily populated area then turn off your engine as these are the areas that are most likely to be policed with fines.
People sleeping in a car may die from carbon monoxide poisoning without ever experiencing symptoms. But people who are awake may experience common symptoms including headache, nausea, dizziness, vomiting, chest pain, difficulty in breathing, confusion, and seizure.
You cannot suffocate in a car because the car is not airtight. Even with the windows up, your car may get humid, stuffy, or uncomfortable if you're sleeping. But the chances of you suffocating are zero. The same goes for your trunk.
Contrary to some beliefs, a car isn't airtight. So you can sleep in your car with the windows up without any issues to your health.
Typically, your car can sit about four weeks to two months without driving before the battery dies. The reason your car can sit only for so long before it dies is the fact that your car battery is in use even when you're not behind the wheel.
Trouble comes when: Cars, trucks, or other engines are left running in enclosed spaces, such as garages. Carbon monoxide can build up in a garage and leak back into the house. Even sitting in an idling car in an open garage can be dangerous.
If you happen to be stopped for an extended period of time, you may want to consider leaving your car in neutral and engaging the parking brake, or just leave it in drive. It's up to you. However, leaving your car in park should mostly be reserved for parking, but it's not totally wrong to do so.
Studies by the Centers for Disease Control found that CO concentrations reach the Immediately Dangerous to Life and Health (IDLH) concentration of 1,200 parts per million (ppm) in only 7 minutes when a small 5 horsepower gasoline engine is run in a 10,000 cubic foot room.
Cars are not air-tight and gas exchange happens regardless of whether the car is functioning or not. Only in an air-tight car would you eventually die from lack of oxygen. The real risk, however, is when you run your vehicle continuously with the recirculation function turned on.
So changes would be even smaller in most homes. Simply put, humans don't take in as much oxygen as we think we do. Based on oxygen alone, estimates are that the average person could survive in a completely sealed, airtight room for 12 full days! Running out of oxygen in a room is quite unlikely.
The problem is not so much the reduction of oxygen but the increase in carbon dioxide. By the time that the carbon dioxide levels in the air that you breathe reach 15%, you'll effectively die. Assuming the box is about 4 cubic metres, it would take about 16 hours or so.
Open a window enough to ventilate
Breathing all night in a vehicle will fog up windows and collect moisture where you don't want it. Ventilation is key. Open your sunroof or a window just wide enough so that an animal or person can't get in. Get some cheap mesh and cut it 2–3 inches wider than the opening.
Sitting in an idling car means you are breathing in more of the dirty exhaust that leaks into the car cabin. Any warmth you may get from a car heater is not worth the damage to your health. If parked and waiting, it is healthier to get out of your car and go inside a store or building.
What are the symptoms of CO poisoning? The most common symptoms of CO poisoning are headache, dizziness, weakness, upset stomach, vomiting, chest pain, and confusion. CO symptoms are often described as “flu-like.” If you breathe in a lot of CO it can make you pass out or kill you.
The carbon monoxide in your body leaves through your lungs when you breathe out (exhale), but there is a delay in eliminating carbon monoxide. It takes about a full day for carbon monoxide to leave your body.
Symptoms of CO poisoning include headache, dizziness, weakness, nausea and vomiting, rapid heartbeat, shortness of breath, seizures, chest pain, disorientation, and loss of consciousness. CO poisoning needs to be treated right away by getting outside to fresh air and calling 911.
To avoid running your car for too long, you should only idle your vehicle for a few minutes at most before either moving your vehicle or turning the engine off. Many people opt to let their car idle for longer than a few minutes when they anticipate needing to stop and start their engine multiple times.
How long should you leave the car running after a jump? It's best to drive the car around or let it idle for at least 30 minutes after you jump-start it. Ideally, you should drive the car around for 30 minutes to allow the alternator to charge the battery to a good level.
If your car is newer, the battery will probably last for four to six hours with the radio on. If you have an upgraded sound system with additional amplifiers, subwoofers, or speakers, however, your battery might drain more quickly. Adding a subwoofer, for example, can reduce the battery life to one to two hours.
Sleeping in a poorly ventilated room leads to the build-up of Carbon Dioxide. When we sleep, we breathe in oxygen and breathe out Carbon Dioxide. This is a natural process, however in a poorly ventilated space the carbon dioxide builds up and fills the room causing us to rebreathe the CO2.
Facing a bed towards a window is a better option than placing your bed underneath it, however, it is still not recommended. In Feng Shui, it is generally believed that, where possible, beds should not be placed directly in line with either a door or windows.