Beep, Beep, Beep

Last night as I was watching television, I heard a beeping sound. I was not sure where it was coming from but after a few minutes I got up to investigate. It was not the kind of sound that my smoke detectors give off, but I checked them anyway. I continued to walk around until I went upstairs and saw my carbon monoxide detector blinking and chirping. For a moment I got scared. Was it a low battery or was there carbon monoxide in the air. I opened up all of the windows just in case, until I found the AA batteries to replace the existing ones. I climbed onto a chair and one by one put in the new batteries. The beeping stopped and I tested the unit to make sure that I had installed the batteries correctly. All was well, but I now had a pounding headache. For the few minutes when I was not sure it was only a weak battery, I did not want to take a deep breath.