Place the bird’s cage near a window enough for sunlight (as they need sunlight to make certain vitamins). Or make sure that the play area is in a sunlit area. Don’t place the bird next to a window with drafts. Massive temperature fluctuations and/or long term exposure to cold, especially windy cold so mind your fan use as well, can cause birds to become sick very fast. This happened to our bird. We opened the window on a spring day when it was 58 degrees but it was windy and not as warm as we thought. We only have the window open for about 10 minutes but Holly got very sick and it required 5 weeks worth of treatment after $800 of bogus diagnostics.
Unless is seems like something else, don’t let the vet talk you into a barrage of tests. Ask them to give the bird a round of antibiotics (usually $20) and if they don’t respond THEN do tests. They always want to do x-rays and blood work then they tell you that they can only eliminate certain things like aspergillosis (fugus) which is almost impossible to treat. Aspirgillosis is very deadly and dangerous. Talk to your vet and check online on how to avoid exposure.
Air conditioning and heat: AC units are ok as long they aren’t directly on the bird or near them as a constant stream of cold air. Here’s a “diagram” of how our windows/cage are set up
0 # X
The 0 would be our window with the AC unit (as if you were looking straight at them) the # is the other window in between the 2 (which never opens and is always sealed shut yet always has the blinds up in the daytime for sunlight) and the X is the bird’s cage. The cage is next to the window so the birds get sunlight but is sealed all the time to avoid drafts. The AC unit is duct taped on the right of the blower and the vents are pointed all the way left so it bounces off the wall to the left, away from the cage. This way the place gets cooled without having the air flow directly at the birds. Under the # window is the heating vent. So in the winter when the heat kicks on the birds are heated right away. I also put a piece of dryer vent tubing (not closed but like if you cut down a drinking straw lengthwise and open it, making a long “u” then placing that “u” upside down over the vent) over the vent about 1/3 of the way. This way 2/3 of the heat goes to the room and the 1/3 goes through the tube and exits directly in the center (at the bottom, obviously) of the bird’s cage table. Heat rises so this helps bring the heated air flow to the birds automatically.