An often asked question is whether or not a canister stove can be used in the winter. Well, the answer is, "it depends." The fundamental problem is that the fuel in canister stoves needs to be warm in order for the stove to operate. For more information about canister stoves and how they work, take a look at
this. To be completely safe, you probably shouldn't use a canister stove in the winter, or if you do, definitely to make sure to test out your stove and fuel before you use it as your sole source of cooking heat. I was able to use my stove (
SnowPeak LiteMax using the
JetBoil 4 season mix) when the ambient temperature was about 27F (-3C) at about 1500 ft (500m) elevation. Also, you should be able to use the stove at a lower temperature at a higher elevation (since there is less atmospheric pressure keeping the gas in the canister).
So, what can you do to use your stove in the winter? Well, first, make sure that you are using a "4 season" fuel mix. This basically means that the fuel is some sort of isobutane mix (isobutane has a lower boiling temperature then butane). Second, use a full canister. Third, you have to keep the fuel canister warm -- if the canister is cold, your food will stay cold as well.
Although it is probably self evident as to how to keep the canister warm, I went ahead and explicitly wrote it out below.