I'm in Texas and my worms died this spring when it got real hot (80F+ all night). They were in the garage. I think the red wigglers were more heat-tolerant than the larger Jumpers. The jumpers I put in the bin died the first night, but they were in bad shape after a late shipment. That seemed to make the whole bin go rotten and I lost months worth of red wigglers the next day.
I'd like to go with the more breathable cloth bag option next spring since the rubbermaid just get's too hot. The worms would be climbing the walls each night and I think that was because they were so hot.
If they are out of the sun and away from direct heat, an established colony with lots of moisture can go above 90 degrees F. I cover the bin with a wet towel or bring it in the house if it gets above 95 degrees, but it hasn't this year.