I wonder if something like this would work for you-
http://images.google.com/images?q=Th...N&hl=en&tab=wi


I might look into these at some point too.

I didn't see how long they are supposed to hold the heat yet..

I looked them up on Amazon to get more info, reviews and a range of prices -
http://www.amazon.com/s/ref=nb_ss_hp...+Pad&x=15&y=15