Cycles of all sorts

A lot of that water you'll be drinking will leave through your skin and will need to pass through your clothes. At temperatures much below freezing, the pores in Gore-Tex and other breathable-waterproof materials quickly clog with frozen moisture, leaving you no better off than if you were wearing coated nylon. Use outer clothes with highly breathable back and sides (light pile or knitted fabrics work well) and windproof fronts. Our favorite brand over the years has been Kucharik.

No matter what your outer layer, you'll saturate your clothes in a few hours. Wear the lightest clothes that will keep you comfortable, with a wicking layer like Capilene or Drilete next to your skin. Overdressing and sweating will leave you just as cold as underdressing and will also waste precious water.

Carrying a second base layer will let you change into dry clothes about midway into the ride.

Heat packs are small envelopes filled with powdered iron and oxidizers. They can warm hands, feet or water bottles for hours. Some people use them as part of their standard winter set-up, others carry them for emergencies. Grabber Mycoal is a widely available brand.