You should be ok. I also stay away from Kerosene heaters because they tend to not burn clean. Maybe it was a lower grade fuel I was using at the time. I use propane which gives of the heat without the fumes. leaving something open to allow a small amount of fresh air without losing all your heat is good. Common sense is the biggest thing to use.. If you feel like your getting dizzy or otherwise affected by fumes.. turn it off and get another source of heat.