I bought the Beerenberg pullover specifically for an extended field visit to Greenland. Setting off on ship from Iceland the sea ice was thicker than expected on the Greenland coast and after a few days at sea we headed back to Iceland to try again the next month. Standing on deck in the Beerenburg felt very Shackelton-esque - and very warm in temperatures a few C above zero. The bulk of the garment and the heavy wool trap a lot of air for insulation if worn under a windproof/waterproof layer and the arm-length, thumb holes and neck help keep the warmth in. I love the raw wool - firstly for coming from Wales and secondly for not having a chemical wash/treatment/dye. I'm happy to wear the pullover with just a t-shirt, but I do usually wear a long sleeve merino base layer and a buff for extra comfort. I'm looking forwards to spending more time in Greenland with this pullover in the near future!