Can you die of suffocation sleeping in car?

Answer 1

Technically speaking, you can not die of suffocation just by sleeping in the car. A car in not 100% air tight and oxygen keeps flowing in through the various opening in the car. These openings could include points where the brake and clutch pedals connect to the engine compartment, air vents, etc.

However, under certain conditions, you can die of suffocation in the car. One of these condition is heat buildup. When you park your car in the sun with the windows rolled up, the heat entering the car gets trapped inside causing the temperature to rise considerably.

If a car is parked in the sun with outside temperature of 90oF (32oC), the temperature inside the car could rise up to 140oF (60oC) because of the trapped heat. Normal body temperature is 98.6oF... At 107oF (42oC) we begin to lose consciousness and the body stops to function. Under these circumstances, the small openings discussed above are insufficient to prevent heat build up.

REMEMBER: It could take as little as 10 minutes for this heat buildup to occur.

Secondly, suffocation could occur if exhaust fumes build up inside the cabin of the car. As mentioned above, the car is not 100% air tight and if you have the engine running in an enclosed space like a garage, or if the fumes are somehow leaking into the cabin directly, it could lead to suffocation. A good term to search on the internet in this regard is "CO (Carbon Monoxide) Poisoning."