Thanks craig for the info, I couldnt see the heat pads before as they were hidden under the trays,
Granulated styrofoam - thats a new one on me, but obviously it seems to work ok.
Hot Peppers:- I cant understand what all you chaps out there do with all your hot peppers obviously you sell a few but surely you dont eat lots and lots of them as well! , I tend to throw in the towel after eating about half of one in a cooked meal, then only now and again, otherwise I am reaching for glasses and glasses of cold water straight away, I once bit into a larger bit of Habenero pepper by mistake and it took me all of ten minutes and five glasses of water to recover.
So now I tend to wimp out on eating most hot peppers and stick mainly to sweet peppers which I realy like.