Last time I played in winter, I got accused of cheating - likely truthfully but unintentionally. My winter jacket cushioned hits from BBs so much in some cases I didn't feel them at all.
The obvious solution is thinner clothing. Except it was -15C, evening, and thinner clothing would mean COLD. Especially in case you lie in wait in some bushes, sniping, or crawl through thick snow.
What kind of winter clothing (or other solutions?) will be thin enough not to cushion BBs too much while still giving a good cold protection?