If you think the bin is a little too hot, try placing a frozen plastic bottle in there. If the worm activity picks up or they congregate near the bottle, you will know it was too hot. You could also use a meat thermometer to check bin temps. Try to keep it below 80F. Shoot for 70F.

Good luck!

I didn't think the bin was hot - actually the damp materials felt slightly cool to me, compared to the Hades-like atmosphere of my living room. But this morning before I left, I put a frozen water bottle in there anyway, figuring it could do no harm. And sure enough - tonight when I got back home, there were several right under it when I lifted the bottle out.

I'm caving and turning on the AC. Even the invertebrates are lethargic, and I have not slept well for days. I think the cats are lethargic, too - it's just hard to tell with them. Laying around dozing is their main activity ;)