Tasteless and odorless
by S.J.
(TO,Ca,USA)
Warning Warning Warning
Take care when using fire in a closed space such as your car. Even a candle will use up your oxygen in a rapid manor. Be advised, carbon monoxide is both tasteless and odorless, and must be respected.
On a side note, an item to add to your kit is disposable hand warmers. They give off a surprising amount of heat, and add a substantial amount of comfort. If you haven't used them before you don't know what you are missing.