One of our viewers sent in this tip.
Although you can supposedly caulk outdoors even when the temperature is down to almost -10 degrees Celsius, if your caulking material itself is that cold, you won't be able to get it to flow out of the gun, let alone stick to anything.
First, keep the caulking at room temperature until you are ready to go to work.
Then keep all the extra tubes in a beer cooler, or in this case, a warmer.
Then when you take the cartridge out and load it into your caulking gun, wrap it all with foam pipe insulation.
If you need to keep it warmer, particularly if you are using it slowly, tape a couple of hard warmer "hot shots" right inside the insulation. The caulking will flow like you were working in the summer and as long as the outdoor temperature is above the working temperature written on the cartridge, your job will stick.
If the surface you are caulking is extremely cold, lead the caulking gun with a hot air gun -- just hot enough to take the chill off of the material, not enough to start melting paint or trim.