I usually bring a pot almost to a boil, then pour it into a bowl with the curds in it (on the side, not directly onto the curds). I keep another pot of water going, so when the first batch cools off, I can pour it out and add more hot water. I don't really measure the temp of the water anymore, but haven't had a problem with the water being too hot.
Was your batch that fell apart from the same make of cheese?