I have a single head and use it in the garage and have not died or had a headache even. I also have not had an explosion, but I am still on my first tank of gas. Woody is right, its CYA, the manuals say outdoor use only (or something), and then it says we cannot predict in all the ways are unit might be used. Funny stuff.

Anywise I just bought a Reddy TB100 30K-55K forced air propane heater of off Ebay. I'll report back on how it works out later on.

Eric
http://s1199.photobucket.com/user/sparky234/library/My%2057%20Chevy%20Stepside?sort=3&page=1
'57 Chevy 3100 (Little Red)
'81 RD350 LC - Fun, Fun, Fun
'83 GS1100E - Pocket Rocket