bedding

I am expecting a litter of puppies at the end of July and this is my first time whelping. We bought an enormous Durawhelp box for my female and I was hoping to get some suggestions for bedding. What stages should I change the type of bedding (ie-whelping bedding then puppy potty bedding)? I...

Need a bed for my pup who tends to get hot easily. Don't really want to get a cooling mat or water bed... Any suggestions on the material or bed that won't get furbabies too warm? So far the sleeping bag material (nylon or polyster) seems cooler than the typical fleece blankets.