Here shown under another sweater these dickies are the best item you can get for keeping the cold out.  They act as a buffer between your under clothes and the cold outside air.  They are really warm and being made with Possum and Merino they are luxuriously soft!  The quality natural fibres mean they also breath really well and release moisture.  Great for windy days and skiing.  Made in New Zealand with Possum Fibre 40% and Merino Wool 50%, with 10% Nylon for added durability.