After months of suffering, you get use to it. Getting your nosethrills stuffed with ice. Your nose hair freezing together, making breathing hard. Your eye brows freezing up, making you viewing life as icey. We tried the Airtrim in Siberia, but it didn´t work below -40. It iced up quickly. Too much hard work causing extreme sweating. The best facemask was the one from Taiga Scandinavia. It was developed by Ola Skinnarmo for his North Pole trip. To avoid frostbite on the nose during night, we had to keep it inside the sleeping bag until ice was gone. And try to keep it there. Not easy. I am now thinking that shaving of the eye brows would help. One thing is for sure, to handle extreme cold, you need to be out there all the time. Read more here at https://www.mikaelstrandberg.com/wp-content/uploads/2009/10/Explorers_journal_winter_05_06.pdf