And Now The Central Heat Is Scaring Me

We are in the middle of, oh, 36 hours of cold weather.  In this, The Winter That Isn't, we have had a few bouts of cold weather, which is fortunate (we'll set aside talk about how this really warm winter is a brutal sign of climate change for another time).

However, I have noticed more and more that whenever the central heat kicks in, it's getting noisy.  Like, really noisy.  This noise starts at the beginning of the cycle; unlike the tap-tap-tapping of one of the filters that I fixed by buying a new filter, there is this loud ... sound that I can't describe.  All I can say that it has gotten louder and louder every time it starts up.

I don't know what's the problem, no matter how much Internet sleuthing I do.  I guess I should look outside at the compressor to make sure, like, a dead rabbit isn't caught in the fan.  But if it's not obvious, I have no idea what to look for.  So I'll have to, ugh, deal with it.

Right now, as I type this, my heart is beating really fast.  I am scared I am getting poisoned by carbon monoxide.  I have a CO detector, and I think it works ... but does it?