Lots of people in my area have remote starts, since it gets so cold here in winter, and remote starting not only heats up the interior so you don't freeze your butt when you get in the car, but also defrosts the windshield.
I've mostly had manual trans cars over the years therefore remote start isn't even an option. But in winter dealing with getting going in the morning and having a cold soaked car sitting there on in my driveway with thick frost and or snow coating all the glass, I can see the benefit of remote starters!
Another area I've seen accidental CO deaths is when running a generator, in the garage, or by an intake for air entering a home. Backup generators are installed far enough from homes to not cause risk, but portable generators can be run anywhere around the house.