K.H.
We use a waterproof mattress cover. It is plastic on the bottom, is covered by soft cloth and goes on like a sheet. You can get ones that zip on but they are all plastic and hot and uncomfortable to sleep on. (My friend tried one for her daughter) The mattress cover works great. I use a waterproof mattress underpad also. This is also plastic on the bottom and soft cloth on the top. This just sits on top of the mattress or mattress cover, under the sheet. The underpads can move some under the sheet, so I don't use it by itself. When there is an accident, most of the time it is contained to the underpad. I remove the sheet and the underpad, wash and replace them. The mattress cover is extra potection. If I have to do a middle of the night change or time is a problem, I remove the underpad and sheet and just replace with a clean sheet over just the mattress cover. This way there is still protection. I get the waterproof mattress covers at Bed,Bath, and Beyond. I get the waterproof mattress underpads at Target. Hope this helps!