The trucking industry is full of grrreat products. 
If its for your kid in the upstairs bunk they make some pretty cool 12 volt blankets now a days, with low batt draw and some even have their own battery. 

Check this out 54 watts (4.2 amps) 58x27 polar fleece heated blanket. 

http://tinyurl.com/hxt55

I have been thinking about one because most of the "complaining" of being cold in the van is when first getting in.  With the 12 vt heated you can "pre-heat" for a toasty warm bed to climb into. 

Doug

  ----- Original Message ----- 
  From: Geza Polony 
  To: vanagon@GERRY.VANAGON.COM 
  Sent: Monday, March 13, 2006 8:23 PM
  Subject: Re: Thoughts on Mr. Heater Buddy?

  Al, it's largely for my kid, who freezes in the upstairs bunk. I'm ok with
  the down cover, the wife, and, uh, the dog...mostly for my daughter who
  complains about cold up there.

  The radiant idea, whether with flower pot or cast iron pan or whatever,
  doesn't solve the problem of unvented propane flames burning.

  I'm well aware of the problem of asphixiation. This particular van, though,
  isn't exactly air tight; in fact, with the top up it has quite a nice cross
  ventilation even with the window closed. Well, if it did close...

  So in fact, there's plenty of combustion air. Wifey's concern is mostly
  about some dummy dropping a sock into the heater, like probably me.

  I sort of like the idea of strapping it on somehow, then putting a cover of
  some sort over it. Time to get out the thinking cap. Before I drop it in the
  heater, anyway.