We had our first dump of snow last night and I was reminded of last February when my chain fell off at minus 30 degrees. Here's a quick and simple diy heater that takes two minutes to make. I liberated a old candy? tin from the kid's room and cut down a empty soup can so it stands about one inch higher than the base. I packed some fiberglass insulation around the soup can then added around two ounces of denatured alcohol and I was done. It lights easily and will bring a small pot of water to a boil in six minutes. You could easily make a smaller version out of a empty cat food and a vienna sausage tin. I'm going to pack a heater when I take my bike ice fishing and build another one for the car. Obviously it's for outdoor use only and will consume oxygen in a enclosed space.