I used to keep bees, I worked with a guy doing it commercially, we had 500 hives at one point.
We used to get stung all the time and not notice it, until one day I got stung on the cheek and the next thing I remember was waking up in casualty 1.5 hours later.
The most stings I had was 40 in one day with no effect at all, but suddenly my body said enough.
Even though I know they can do that to me I always take care of them.
Without bees we would loose about 30% of our crops.