Cover the bin with solar-reflective Mylar plastic sheeting to protect against sun and heat damage. The Mylar covering will also make your ice packs last a lot longer. Mylar also works well to keep heat in, during the winter months.
Let me know if I can help! The ice packs provide a quick relief and the carbon/nitrogen ratio is more of a long term solution. However, even with an optimal ratio, if the temperature outside is above 90 I would do ice packs to avoid stress.
Lori, I find them when people trow away their mesh shelves. You could buy a whole unit at Traget, but you only need a couple of sheets, so probably not worth. I fond an individual sheet on Amazon. Bigger squares, but should work. amzn.to/3jOk0Zl
In nature different types of worms will migrate to their ideal climate. The best way to keep them in a system is to get the type that tolerates your climate. If your in the north european and canadian night crawlers are your best bet. If your dealing with high temps red wigglers are your best bet.