If you wear down to stay warm...

NorthCascades

Throw it in the dryer (by itself) on medium heat for an hour. It'll come out warmer. 🙂

Down compresses very well and springs back well too. After a lot of cycles of that, it doesn't loft to its full potential. The dryer and mild heat bring it back up to its full potential. You don't need tennis balls unless it's wet. It'll stay extra puffy until a bunch of use.

You should wash it semi regularly too (once a season is about right for most people, for a jacket). Oils and residue from sweat also prevent the down from fully lofting. And that loft is where the warm comes from.

I just learned a friend of mine has never washed a down coat he's used for years 😳 and thought a PSA might be in order.

spiriteagle99

I've noticed my down coat has lost a lot of loft. We washed it at the end of last winter, but it didn't really fluff up properly. I'll try the dryer thing again. If I'm cold at 39, I'll be freezing when it's 5 degrees.

Oliveciabatta

Be careful washing down, just like lanolin in wool, feathers have natural oils which help them stay slightly waterproof and in shape. Washing with detergent can remove this and strip some of the natural protection. Always use a specialist down wash on a lowish temperature and slow spin.