Rep Power: 0

I left my car sitting for too long and the temp dropped to -20 degrees and is between there and 0 degrees (I live in Montana). I put in new battery and it did nothing. Then I had it towed to a garage to warm up and it started like a charm but as soon as it was in the cold again it wouldn't start. I would like to avoid getting it towed again or waiting until it warms up. A Friend suggested I use a heat gun to blow hot air on the engine. Is this a good idea? And if it is, where would I point the gun. I have limited knowledge about cars but could easily google a place to point the gun if someone could suggest a place to blow it.

Thanks,

Sam