Some detractors, not least in The Daily Telegraph letters page, have suggested that Sir Ranulph’s latest expedition involves neither exploring nor adventuring, but merely travelling. Indeed, though he will be skiing for up to 12 hours a day – including during a three-month period of perpetual night – he will, along with his team, shelter at night in a caboose. These are heated, well-equipped trailers pulled on massive Caterpillar ice tractors, 30 feet behind the skiers. Wireless technology does not work at extreme cold, so he will keep in touch with the back-up team via a cable that is attached to him.