Maybe that they have the ability to leave if they get too hot.

If the whole bin is hot then they get in trouble.

I guess what I meant was that it is generally accepted that worms thrive at room temperature (about 70F) but tolerate 50F - 80F. My surprise was to find so many worms congregating in the hot decomposing slurry - I would have thought it would be too hot for them there.

"Generally accepted" are probably the key words here. I think we can try to manage temps and moisture to make the environment in the bin more towards the worm's liking on a consistent basis, but there are big variables that make us scratch our heads and say.."Go figure!" When I obsess over moisture levels in my COW, I can open up the collection tray and find worms just lolling around in the smelly muck, seemingly perfectly happy. I also think perhaps that worms born into a system manage better with varying conditions than the older ones. Other than those thoughts, I'd have to say.."Go figure!"

I guess my poking around to check on the guys intermixed too much feedstock with bedding in one of my bins...I came home from work to find the bin very warm - I measured the temp and it was 110F! I'm afraid all is lost in that bin.

Lesson learned but of course feel really bad.

I was trench feeding and covering with bedding. I think I'll do more surface feeding (or trench but cover with damp paper towel) and take greater care not to intermix.

What I do with mine when feeding the worms I lightly cover the scraps or the surface if you will with dried leafs, that seems to helps to keep a balance temp enviroment within the bin contents.