1997 Chevrolet Astro Owner's Manual - Page 203

This can cause deadly CO (carbon monoxide) gas to get inside. CO could overcome you and kill you. You can't see it or smell it, so you might not know it is in your vehicle. Clear away snowfrom around the base of your vehicle, especially any that is blocking your exhaust pipe. And check around again from time to time to be sure snow doesn't collect there. Open a window just a little on the side.of the vehicle that's away from the wind. This will help keep CO out. Run your engine only as long as you must. This saves fuel. When you run the engine, makeit go a little faster than just idle. That is,push the accelerator slightly. This uses less fuel for the that you get and it keeps the heat battery charged. You will need a well-charged battery to on restart the vehicle, and possibly for signaling later with your headlamps. Let the heater run for awhile. Then, shut the engineoff and close the window almost all the way to preservethe heat. Start the engine again and repeat thisonly when you feel really uncomfortable from the cold. But do it little as possible. Preserve the as fuel as longas you can. To help keepwarm, you can get out of the vehicleand do some fairly vigorous exercises every half hour or so until help comes. 4-27