CARBON MONOXIDE SAFETY
Carbon monoxide can be deadly in an RV (or your home for that matter) but there is absolutely no reason for you to be at risk if you follow these guidelines.
Engine exhaust
Cracked combustion chambers in the furnace
Unvented heaters
Generator exhaust
When parking in deep snow make sure there is a good air flow under your RV to carry away the generator exhaust.
Have your exhaust systems checked for leaks and be sure the end of the exhaust pipe is 2" past the body.
Use a CO alarm.
In my opinion, most CO alarms that come standard in some RV's are of very poor quality. Consider replacing them with one of these: Consumer Reports (November 1998, pp.46) recommends 2 good battery-powered CO alarms from Nighthawk (900-0089), $45 and from Aim Safety SAS 6-96D, $80.
Crack open a window and a roof vent to provide some ventilation, even in the coldest weather.
Do not use unvented heaters.
Check your owner's manual for information specific to your RV.