Luckily we got to Gothenburg a few days after the big freeze. This involved temperatures of -15 with over a foot of snow settling in one night. I've included a pic in the post below from Varberg where some parts of the sea had frozen over. It was about -6 when I was there, further north was around -30... I picked up a good Swedish tip. Woollen socks on first, followed by cotton socks. Shame I don't own any woollen socks.