Staying Warm in Your RV on Cold Arizona Nights: Heat, Propane, Condensation & CO Safety

Updated October 2026 · Rules and fees change, so confirm with the land manager before you go

Arizona winters aren't all sunshine. The low desert can drop near freezing overnight, and places like Flagstaff and the Grand Canyon's South Rim (around 7,000 ft) get hard freezes and snow. Here's how to stay warm without creating a safety problem.

1. Use the heat your RV was built with

Your RV's furnace is vented to the outside, which is why it's the safest fuel-burning heat source on board. Before the season, have it checked, and make sure the outside intake and exhaust vents are clear of nests, dust and debris. The U.S. Fire Administration recommends having a trained technician inspect your RV at least once a year.

2. Never heat with the stove or oven

The CPSC says never to use gas ranges or ovens for heat, and never to use portable fuel-burning camping gear inside a vehicle or tent unless it's specifically designed and labeled for indoor use. Never run unvented fuel-burning appliances where people are sleeping.

3. Electric heaters on shore power

If you have hookups, a portable electric heater can take the chill off. CPSC safety tips:

Keep at least 3 feet of clearance from bedding, curtains, clothing and anything else that can burn.
Plug it directly into the wall, not into an extension cord or power strip.
Choose a certified heater with tip-over and overheat shutoff, and set it on a stable, level floor.
Turn it off when you sleep or leave.

Watch your amperage. Running a heater, microwave and water heater on electric at the same time can trip a 30-amp pedestal.

4. Generators and carbon monoxide

Improper generator use is a leading cause of CO poisoning in RVs, according to the U.S. Fire Administration. Point the exhaust away from and downwind of your rig and your neighbors, and never run a generator in or near an enclosed space. Follow the campground's generator hours.

5. Alarms you should test now

CO alarm: USFA says all RVs should have working CO and smoke alarms, tested monthly. CPSC recommends alarms that meet UL 2034.
Propane (LP) leak detector: many RVs have one mounted low near the floor. Check its date and replace it per the manufacturer.
Fire extinguisher: keep one where you can reach it, and know the P.A.S.S. method (Pull, Aim, Squeeze, Sweep).

If a CO alarm goes off or anyone feels headachy, dizzy or sick, get everyone into fresh air and call 911.

6. Fight condensation

Cooking, showers, breathing and wet gear all add moisture. When it's cold outside, it ends up on windows and walls and can lead to mildew. Crack a roof vent and a window, run the vent fan while cooking and showering, and dry wet clothes outside when you can. A small dehumidifier helps on hookups.

7. Hold the heat in

Insulated covers for roof vents and skylights stop a lot of heat loss.
Reflective window insulation or thermal curtains help at night.
Close off rooms you aren't using, and check door and slide seals.

8. Protect your water system

In freezing country, use a heated drinking-water hose or disconnect at night, keep the bays warm, and know how to winterize. See our RV water and plumbing guide.

9. Plan your propane

Furnaces go through propane quickly on cold nights. Know your tank capacity, top off before heading into the high country, and check propane lines for kinks or damage. USFA recommends testing fittings with a gas leak detection device.