I have one.  It has a tip over and CO sensor.
They work ok.
The trick is it gets warm on top of the bus.
Not the floor.  So you need a fan too!

>>> Neal Powers <Neal354@WMCONNECT.COM> 11/3/2005 1:05:08 pm >>>
Today i was in Home Depot looked at buddy heaters propane you can use the one
pound or 20 pound sign on box states indoor safe the good part $79 and
change, Later Neal