Suffering from the cold is not an option when you wear an insulating down jacket. A good technical down jacket retains your body heat effectively while remaining lightweight and highly breathable. However, if heavy rain is expected, wear your down jacket as an additional insulating layer under a hardshell jacket. Down absorbs moisture very easily, and a wet jacket becomes heavy and loses its ability to keep you warm.
Want to know how well your down jacket insulates? Look at the fill power, measured in cubic inches (cuin). This is a reliable indicator of down quality. Jackets with a fill power of 800+ cuin guarantee top-quality insulation. Keep in mind, though, that a high fill power does not automatically mean a warmer jacket—the down percentage also plays a crucial role.
Types of down: ratio of down to feathers
If you want a jacket that retains as much body heat as possible, check the down percentage. This figure indicates the proportion of down versus feathers. A ratio of 80% down to 20% feathers is considered good quality. For maximum protection in extreme cold, opt for a jacket with an even higher down ratio. A 90% down and 10% feather mix is ideal in these conditions.