Eeek! Even though you don't "feel" the effects it could affect your nervous system. When I worked in a Market company and we had to work with chemicals to do our ads and such, we had to have a ventilation system because even a simple spray of something is bad. Be careful.
If I know I'm going to be doing a lot of something I usually try and put a fan in the window to suck air out. It's a bit tricky with the basement because I don't want to disturb any sawdust from the floor and have it stick in the fresh lacquer. Somewhere on the list of things to do is to get some proper extraction fans, remove one of the basement windows entirely, and replace it with swappable panels. Panels would include a plain mesh bug screen, a double-glazed window, and an extraction fan. In the summer time I'd most likely just put the bug screeens in, in the winter time I'd use the windows, and when working I could use the extraction fan.
When I lacquered the floor in the finished room even a fan wasn't really an option because I couldn't have the wire laying on the floor and couldn't open the window far enough for it to make a meaningful difference anyway.
I think for future floor lacquering (I have several more rooms to finish, and almost all of them will want the floor finished) I'm going to build a frame out of some wood so I can open the window a crack while staying sufficiently closed I can use the security latches, then mount a window fan at the back of the frame and incorporate some kind of clip to keep the wire under control. That should give me the combination of security and weather proofing while also getting rid of at least most of the fumes.
