Cut a piece of fiberglass to fit the inside of each window. Among the more vulnerable parts of a camper are the windows, which tend to be thin and poorly insulated. Secure the fiberglass with Velcro strips. Leave one window uncovered for the next step.
Install a catalytic heater that emits high BTUs for the interior of the camper. Place the catalytic heater against a window and leave the window cracked open to let any fumes emitted by the heater escape.
Seal all roof vents. Roof vents are subject to a great deal of heat loss. The easiest solution is to roll up a few T-shirts and tape them against the vent.
Run water from the faucet periodically to keep the camper's pipes from freezing.
Apply 1/2-inch rubber strips to the entire length of the door to seal in drafts.
Bring lots of blankets. Often the simplest solutions are the best. Additional insulation can keep a winter camping weekend from becoming miserable.
