@Jan-Krejčí it should not be a problem. I use Race 2 on the outside of my jacket when biking and XC skiing. I guess biking is not cold enough (around O C), but I XC skied in -20 C without any problems. Previously, I used S9B and skied at close to -30 C on a few occasions with no issues. I think the specs talk about -20 C or even -25 C. When it is colder we should stay at home .