Latex paint left out in the cold doesn't always have to be thrown away. Before you give up on it, open the can and check the condition. Here's what to look for.
Freezing does ruin latex paint, but it can survive a few freeze/thaw cycles. Allow the paint to slowly warm up to room temperature, then stir it well. If the paint color and consistency appear normal, then it should be all right to use. If it looks like cottage cheese, it was frozen too long and you should let it dry on newspaper in a safe place, then put it in the trash.