Would recommend atleast double if not tripple bagging the ray with garbage bags. Heat pads are a must, make sure the heat pads are exposed to air, if they are placed under the bags for example they dont work as they need oxygen to generate heat. I would recommend taping them to the inside of the rubermaid lid, just make sure not to cover them in to much tape.
Also make sure your garbage bags are the unscented type, seems that alot of the garbage bags these days get sprayed with perfume to cover up the garbage smell. Not sure how harmful the scented ones would be but probably not something you want to test.