What should I pack for a winter visit?

The answer

Bring layered clothing with a windproof outer layer, insulated boots with good grip, warm socks, a hat and mittens. Wool or synthetic fabrics perform better than cotton when wet. Cover exposed skin in strong wind, since wind chill raises the risk of frostbite. A spare power source helps, because cold drains phone and camera batteries, and warm gear for waiting outside is essential if you plan to watch for the aurora.