Ha, sorry, I should have been more specific! When I say "near boiling" I mean steaming and hot to the touch. Then I remove the water from the heat and stick the defrosted rat in (I use the ziplock baggie too). 10min later, the rat is warm and the water is warm, but nothing is close to boiling by the end of the process.

I prefer this method because my tap water gets hot-ish but never steamy, and therefore seems to take FOREVER to even get the rat above room temp. I guess the bottom line is still: get the rat warm enough that it feels life-like.