Mine thaw on top of my T8s at room temperature either overnight (if I plan to feed in the morning) or during the day while I'm at work (if I plan to feed at night). There are zero smell issues that I've noticed. By the time I'm ready to feed, the girls are in full feeding mode having smelled the thawing rats for a few hours. Just before feeding, I hit the rats with a hair dryer for 30-60 seconds - mostly near their heads, but I do warm their bodies a bit too. This method works very well for me and my small collection.