I don't use warm/hot water any more since the rats always end up so soggy when I take them out of the ziplock bag. I just let them thaw out and use a hair dryer to heat them up, especially the head of the rat. It works like a charm for me and you don't have to worry about soggy rats lol. And your snakes will get familiar with the sound of the hair dryer so it just like ringing a dinner bell. They will be waiting in their tubs for it to be offered