Well, I have to say I have been much healthier since I quit teaching. But even I made mistakes in when to keep my kids home or send to school. One day, Scott, age 8, told me his "bones hurt." DH was out of town and I was stressed. I said, "Get dressed, you're going. I can't stay home another day" (the other one had just been home 2 days). Two hours later I got a call from the nurse, saying he had a fever and was really sick. I worked really, really far from where I lived and their school was another 10 miles from my house. By the time I got him, went to the doctor and was waiting for the prescription at the pharmacy, he was lying on the floor in the store, moaning his head off, with a 104 degree fever and bronchitis. So I listened after that!
I *did* let them stay home alone with a mild cold after age 10. Well, I let the older one stay home at age 10, and I just checked on him every hour by phone. Scott was maybe 12 when I let him do that. He once called me when he was a freshman in HS and had stayed home, saying he "couldn't breathe." I ran out of my classroom so fast, the kids wondered where I went; I got an assistant from the special ed room to teach my class and told my boss I was leaving. I didn't give her time to even question me... he ended up having pneumonia (from riding when he was just a little sick, which turned into big sick).