Today is 14°F (-10°C) here in the northern suburbs of MA. In wintertime it can be tough to brew outside if you are a propane cooker brewer such as myself. When the tank is going full bore it tends to frost up and get really cold as that liquid propane in the tank vaporizes. I don't know if the propane actually freezes, but as it gets colder and colder the flow rate can trickle to a stand still and the boil becomes difficult to maintain.
Anyone else notice that? What do you do to combat it?