I was working in a small cabin, painting. I had windows open and fan on, but the room I was in had no windows. I felt fine for several hours, but suddenly was having fast heartbeat. 100 bpm and it was causing me to breathe hard. I basically did not feel well. The house has a funny odor in it, that we have never gotten to the bottom of, although some think it is mold. We had the attic abated last year for mold and no other sources have been found. I went home and am feeling fine now. I am worried about going back over there and there is a lot of work to be done. There is a carbon monoxide (?) monitor in the room I was in, but it has never gone off. Any thoughts?