We use this one in our fifth wheel and it will keep it toasty warm, even down into the 20s. We will run the furnace before we go to bed, just to make sure the underneath is good and warm and we unhook the fresh water hose so it doesn't freeze.
Edenpure infrared heaterMy sister has this one in hers.
Northern ToolI am pretty sure they are the same heater, but hers was $169 and mine was more expensive, even though I purchased it at Sam's Wholesale.
I have a large gauge electrical cord that I run directly to the post through the slide and plug my heater up that way. We don't overload the circuits inside the RV that way.
This thing is about the size of an ottoman and there is virtually NO WAY to turn it over. The dogs and cats play around it all the time, their tails can't get into it, if something gets tossed on top of it, it won't catch on fire, it is just a great little heater.