When I first switched my bp to frozen/thawed, I would put it(inside a bag) in warm water for a few hours to thaw it, then put it in warmer water(not in a bag) just before feeding it to heat it up a bit. This is great if your snake doesn't mind wet food but I have read about some picky snakes. Also in my opinion if you feed your snake wet food you shouldn't feed it in its tank, bedding sticks to the food.
Now I use a hairdryer on a low setting to warm it up before feeding(still thaw it over a few hours in water). Not only is this easier, its dryer, much faster, and in my case it seems to get the snake in the eating mode too, probably because of the smell dispersing faster in the warm air.