Thank you for the detailed warning.

I actually decided to let go of this idea after OP’s warning and reading a bit about it. Because one problem will be that I will have to enter to switch off and on and even though it could be a short lived exposure I was scared. Though I’d read more on this what it could kill in the room. The thing is it might not help anyway. It is seasonal/situational and it happens in other places as well or outside if sun is not up. So whatever it is (general guess is pollen, dust, dust mite, sudden temperature changes?, general pollution etc) it is already in me or on me or everywhere around me. So I guess it might rather help more with an allergy test and if I am lucky I can find what I am allergic to.