In answering [this question][1] I tossed out that a candle lantern can provide as much as 10 degrees (F) of temperature difference while winter camping. I've heard this tossed about before, but is it true? I assume there are differences between snow-caves (well insulated) and tents (less so)... Anyone have any cold hard numbers?

  [1]: https://outdoors.stackexchange.com/questions/3284/when-is-it-too-cold-for-tarping