My Black Friday special showed up

All good advice given about fumes, oxygen depletion and flammables. Another thing to watch out for, while not harmful to you, is moisture. Those things will put a TON of moisture into the air in short order. Bare metal panels, machined surfaces and hell, even your tools will not take kindly to the extra moisture in the air. Trust me, I know! I used to use one of those torpedo heaters on kerosene and was constantly battling rust on everything! I switched over to a direct vent, LPG wall heater, but it burned through propane like no tomorrow, even set at 50 degrees (I keep it on all the time to keep the garage from reaching freezing tepuratures), so I pulled it out and replaced it with a pellet stove. I should've done that to start with. Running at the lowest setting it burns about a bag of pellets a day at $4.18 a bag ($125-$130/mo) while I was using a 100# tank of propane every 10 days with the direct vent heater. At $80 a fill that's $240/mo! The pellet stove cut the heating cost almost in half and on the lowest setting the garage maintains a constant 60-64 degrees depending on the outside air temperature. I can work comfortably at that temp, but have 8 more settings if I really want to warm it up!