When cooking with canister stoves, there are a number of factors that must be held in tension: Air temperature, fuel temperature, type of gas (butane vs. isobutane and propane), elevation, canister chilling, etc.

I've just written a post where I try to tie these things together in a succinct and hopefully practical fashion. Have a look if you like at: Canisters, Cold, and Altitude: Gas in a Nutshell

HJ

I love it all HJ. Thanks yet again

I keep trying. That's my best effort yet to communicate a rather complex set of tensions.

HJ

I have always had very good luck sticking a hand warmer (the kind that get warm when exposed to air) under the canister. Doesn't get too hot and makes a big difference, light and easy to use.

Makes sense and sounds safe.

Some day I'll compile a list of different way to keep the canister warm. Pretty handy to know about if the temperature takes an unexpected dip.

HJ

That works if you start with a warm canister. However, all canisters chill with use; it's just a property of liquids that vaporize into a gas (the fuel under pressure in the canister is liquid). If you use the stove for very long the canister will get cold from within, and a beer cozy might actually be holding the cold in. You have to really think when using canisters; they change as you use them.

That's why I like putting them in a tub of water. The water is fairly dense and will moderate temperature changes. If it's so cold that tepid water freezes rapidly, it's time to break out the liquid fueled stove or use a different canister warming technique.

HJ