How to keep warm without a heater.

14 July, 8AM, temperature in Derby, minus 3°C!

The night before last, the temperature was minus three and last night an even colder minus five. To keep warm, house dwellers heat their houses by putting more wood on the fire or turning up the central heating; burning more fossil fuels and spending money in the process. Tent dwellers, on the other hand, have to retain their own body heat. Thermal under-clothing, several layers of clothes, beanie or balaclava, hooded jacket, thick socks and gloves are the basic essentials. For sleeping, you need a good sleeping bag but even the 'snow rated' bags don't always make the grade so two sleeping bags are best. The ground is freezing and insulating yourself from below is most important. Ben has a couple of thin blow-up mattresses that do the job very well. With those basics you can be very warm (even hot) on the coldest of nights. There are some drawbacks. It's difficult to read a book and stay warm at the same time because your arms have to be at least partly outside the sleeping bag. Having to get up for a pee in the middle of a freezing cold night would have to be the greatest drawback of tent-dwelling. Another reason for using two sleeping bags, one inside the other, is that your body heat gradually warms through the bags and, when it's really cold, moisture condenses on the outer covering. By morning, the inner sleeping bag is lovely and warm while the outside of the outer one is cold and damp. Getting out of bed isn't easy but, once you're up, a warm bowl of porridge is a great way to start the day.