With 32 degree F weather outside, the car without heat loses 10 + degrees every half hour. The candle heater model under prevents any loss of heat, rather with aluminium bubblewrap on your windows, it will gain heat even with no power in the car. The CO levels stay very low, but its a good idea to open a door and let some air in every now and then.
I bet Grouf is fun to hang out with because he is ALWAYS up to something interesting. lol...