Bivouac -- an extremely lightweight alternative to traditional tent systems. Very popular among climbers and minimalist campers, a bivy sack at its barest is a thin waterproof fabric shell designed to slip over a sleeping bag, forming an effective barrier against wind and rain.

To really be sure you have to bivy for the night in the cold, shivering and cursing, you should do any of these things:

• go on any trip with Christian or Don
• decide that you will follow the "fast and light" philosophy, when you really belong to the "light and slow" group
• only bring 1 liter of water because "you'll only be out for a couple hours"
• leave the bivy sack and down jacket in camp to save weight
• overhear your rope mate ask "what route are we doing again?"
• get drunk the night before, and then try to fit in 17 pitches of 5.7 after 1 PM leading someone who has never climbed before
• listen to anything Tom Prigg says

But a bivy will put hair on your chest. If you're too scared, stay home and start a Team Vagisil sewing club with Ryan H.