|Peaks and snow, Sierra Nevada Mountains
Second, start with a warm canister. Keep the canister in your bag/quilt at night or in your inside jacket pocket (or something) during the day.
Third, keep the canister warm by placing the canister in water. If you chose good fuel in the first step, your fuel vaporizes at least at 11F/-12C. Liquid water will always be above 32F/0C -- that's about 20F/10C degrees above the vaporization point of the fuel. As long as that water stays liquid, you should have good canister pressure, even if the air temperature drops below the vaporization point of your fuel. It's the fuel temperature that matters, not the air temperature. There are other ways to keep a canister warm which you can read about elsewhere, but water is safe and effective and is my preferred method. WARNING: Do not use hot water. Tepid or even warm is fine, but hot water may cause your stove to flare.
Fourth, heat the canister if needed. How can you tell if the canister needs more heat? Poor performance. If your stove's flame is insipid in cold weather, try taking a spoonful or two at a time of hot water out of the pot and putting it into the water that the canister is sitting in. Your performance should improve as the water gets hotter. If performance does not improve even though the water the canister is sitting in is warm to the touch, there may be something else at issue such as low fuel level or a partial blockage in the jet.
Note: If you want a detailed explanation of why this is so and what's going on behind the scenes, please refer to Gas Stoves: How Cold Can I Go?
That's it. Choose good fuel, start with a warm canister, keep the canister warm, and heat the canister if needed. Happy cooking. :)
Related articles and posts:
- Cold Weather Tips for Gas Stoves
- What's the Best Gas for Cold Weather?
- Gas Stoves: How Cold Can I Go? <==Most comprehensive article on canister gas and cold
- Canisters, Cold, and Altitude: Gas in a Nutshell
- Canister Stoves 101: Thread Care
- Gas Blends and Cold Weather Performance. (Why not just use propane?)
- The "Super Gnat" (Camping Gaz or threaded canisters with one lightweight stove)
- Backpacking Gas Canisters 101
- Gas in Extreme Cold: Yes or No?
- Gas in Cold Weather: The Myth of "Fractioning"
- Stoves For Cold Weather I (Upright canister stoves) – Seattle Backpacker's Magazine
- Stoves for Cold Weather II (Inverted remote canister stoves) – Seattle Backpacker's Magazine