|Frozen lake, Sierra Nevada Mountains|
I've been writing on this subject for some time. I've just re-written my main article on gas and cold weather. I won't reproduce the entire article here. I'll just post a summary below. I actually think the summary is fairly useful in and of itself. I don't recommend that you rely on the summary alone. Before you take a canister gas stove out in cold weather, I recommend that you read the full article. But the summary can be a useful refresher and reference once you've read the main article.
1. If you use a canister right side up, the best cold weather fuel, propane, boils off at a faster rate, so you must be able to rely on the other components of your fuel. Therefore choose isobutane and avoid n-butane.
2. If you use a canister upside down (inverted), the propane stays in the mix and your fuel has better cold weather performance. Most stoves cannot handle inverted operation. Do your homework before trying this.
3. If used upright, canisters experience significant cooling from within. Therefore, it is the fuel temperature which matters, not the ambient temperature. Your fuel temperature will be usually be colder than the surroundings after operating the stove for a while.
4. If you use a canister upside down, the canister will not experience cooling (well, at least not to the degree that it does in upright operation).
5. In order to have enough pressure to properly operate a stove, your fuel temperature must be warmer than the vaporization point (boiling point) of the fuel. Generally, about 20°F/11°C degrees above the vaporization point will give you good operating pressure, but the actual performance of the stove is the bottom line. Poor performance probably means that your fuel needs more heat. Therefore you must be able to heat the canister. Water is typically a safe way to heat the canister.
6. NEVER heat a canister to the degree that it is painfully hot to the touch of an (unfrozen) bare hand.
7. The higher you go, the colder the weather your gas stove will operate in, but the colder it gets, the harder it is to keep the canister warm, irrespective of elevation. As you climb, temperatures fall faster than the performance of your stove increases. You cannot out climb cold.
8. If you heat the canister, you are not as constrained by the ambient temperature. However common sense still applies here. Can you realistically keep the canister warm enough in the temperatures expected? What happens if the weather is colder than expected? What happens if a storm moves in?
9. You must know and use the basics of cold weather canister operation (select good fuel, start with a warm canister, keep the canister warm). You must also be prepared for emergencies and the unexpected.