
I love my heating pad...My pupps are 4 1/2 weeks old and I still have it on. I put it in 1 corner, under my whelping box, on the lowest setting and never turn it off. It keeps that corner warm, I check it every day and the pups and mommy use it all the time. The water bottle cools too quickly for me but I know many people use it as well.
My preference:

Heating Pad