For those of us in very northern latitudes who actually live in Antarctic conditions for 4-5 months every year, Jock's question is more or less how we shoot on any truly cold winter day, perhaps minus the salt air part. Mattia's suggestions are very good and based on experience… the most counter-intuitive as he noted is, you need to let your camera stay cold. For me the Pentax K5 has never let me down after hours of shooting in conditions colder than LL experienced…. the limitation is my fingers or toes, and sometimes my brain freezes which consistently results in crappy shots - time to go home. I see myself gradually shifting to mirrorless, but the Pentax and my remaining 3 K series lenses will remain for these really tough conditions.