Butane, C4H10, has a boiling point of -0.5 ?C (which is 31 ?F). Despite this, liquid butane can be seen sloshing about inside a typical butane lighter, even at room temperature. Why isn't the butane boiling inside the lighter at room temperature?

Its under pressure.

That's why the gas comes out when you Flick Your Bic!

I never realized the boiling point was so high. I need to make a mental note not to rely on a butane lighter for winter camping trips unless I plan to keep it in my pocket!

You will see butane as a fuel in hot countries-India, Iran, South America but to use it in most of the US, you need to keep it warm. We used it in some chemical operations but had a steam pre-heater.