When I first entered the room there was a horrible smell that isn't bearable, I thought that it's from the toilet near the room but it turns out there's a dump underneath the window (not a actually a window because the area in front of it is only open from above).
It turns out there are actual dead birds and animals laying down in the dump, I was literally shocked and had to leave the room immediately.
I talked with the host (Ilir) about the issue and he told that there's sewage problem in the neighborhood and that he can't help me or do anything about it.
Also there was no ventilation at all, not even a fan and the temperature in Istanbul was above 30.
I believe this room (the "yellow room") used to be a bathroom because it has a drain in it and is not suited to live in under any condition.
That was a very bad and unpleasant experience.