1993 Buick Park Avenue Owner's Manual - Page 202

A CAUTION: LCAUTION: Snow can trap exhaust gases under your vehicle. 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 snow from around the base of your vehicle, especially exhaust pipe. And any that is blocking your check around again from timetime to be to sure snow doesn't collect there. Open a window just a little on the side of the vehicle that's awayfrom thewind. This will help keep CO out. CAUTION: (Continued) Run your engine only as long as you must. This saves fuel. When you run the engine, make it go a little faster than just idle. That is, push the accelerator slightly. This uses less fuel for the heat that you get and it keeps the battery charged. You will need a well-charged battery to restart the vehicle, and possibly for signaling later on with your headlights. Let the heater run for awhile.