>>21892448Down fill is still the warmest. Synthetic is getting close. In either case the jacket will have a puffy appearance. Wool is adequate to around -10 C (spending extended periods outdoors).
If you're going to be outdoors for hours at a time doing some work or trying to climb mountains you wear pic related. This is box wall baffle, down fill. It's the best you can do short of a pressurized suit.
