I hear that more and more folks are unexpectedly living in their cars these days, and of course, there is always the chance of getting stranded. I hope neither one happens to you or me. But anyway - in the interests of preparedness - I came across the plans for an emergency car heater, using a one-pound coffee can at:

http://www.equipped.org/coffe_can_survival_heater.pdf

On a trial run I was a little alarmed at the amount of open flame produced. This could be a safety issue in smaller cars. I am thinking that inverting a three-pound, vented coffee can over top of the burner would shield the open flame while also releasing and radiating heat.

Has anyone tried anything like this? Also I am curious as to why the instructions call specifically for seventy percent isopropyl and warn against using "anything stronger". Methanol (gas-line "Heet") seems to burn cleaner. Does it present a CO hazard?