Travellers who spent 1500 days on the road with overnight stays in their vehicle, including three winters, said layered bedding is the key to comfort rather than specialised heating equipment. They camped at temperatures down to minus 20 degrees Celsius in Rikubetsu, Japan's coldest town, as well as in Niseko and Aizuwakamatsu. According to their figures, the temperature difference between outside and inside the vehicle is about 5 degrees, condensation freezes at around minus 6 degrees and minus 12 degrees marks the threshold for serious preparation. Essential measures include keeping a snow shovel inside the vehicle, using hot water bottles and not sleeping with the engine running because of the risk of a blocked exhaust.
