Describe the 4 layers of clothing required to keep warm in Svalbard.
Layer 1 - thermal underwear (synthetic/silk), socks
Layer 2 - turtleneck/fleece sweater, cotton/fleece trousers
Layer 3 - scarf, thick wool/fleece sweater, padded ski trousers, woollen socks
Layer 4 - hat, winter jacket, gloves/mittens, boots