1997 Buick Riviera Owner's Manual - Page 192

Snow can trap exhaust gases under yourvehicle. This can cause deadly (carbon monoxide) gas CO to get inside. CO could overcomeyou and kill you. You can't see it orsmell it, so you might not know it is in yourvehicle. Clear awaysnow from around thebase of your vehicle, especially any that is blocking your exhaustpipe. And check around again from time to time to be snow sure doesn't collect there. Open a window just a little on the side the of vehicle that's away fromthe wind. This will help keep CO out. Run your engine only as long as you must. This saves fuel. When you run the engine, makego alittle faster it than just idle. Thatis, push the accelerator slightly. This it keeps the uses less fuel for the heat that you get and battery charged. You will need a well-charged battery to restart the vehicle, and possibly signaling later on for with your headlamps. Let heater runfor awhile. the off Then, shut the engine and close the window almost to preserve the heat. Start engine again the all the way and repeat this only when you really uncomfortable feel from the cold. But do as little as possible. Preserve the it fuel as long as you can. To help keep warm, you can get out of the vehicle and some fairly vigorous exercises do so every half hour or until help comes. 4-29