Hi!! I have been a lizard owner for about 10 years now, and have really had to learn a lot on my own through trial and error about lizards. 
I have had a water dragon (who lived to be almost ten) and currently have a 7 year old Beardie.
I see a lot of references to different heating methods - under tank, heat tape, heat pads, etc... but I use a product that I actually bought from my exotics vet. She actually uses the same product to heat her animals safely during long surgical procedures!!
It is called an SI thermal pad and is enclosed in thermoplastic. I am going to be getting a rescued iguana in a few days and went to the website for SI thermal pads (did a search under yahoo.com) and bought one there. They are not cheap - mine was 110.00 - but these items are INCREDIBLE. I have had the one in my Beardie's cage for about 4 years now and it is amazing. It turns itself on and off to regulate itself (you don't have to buy any regulators like with the Kane systems) and will NOT develop hotspots.
This product is SO worth the money and I recommend it to everyone. I think it also has a lifetime warranty!!!
Buy one for your babies. You won't be sorry and will never have to worry about burnt tummies or roasted animals - my Beardie loves his!!!!!
Love,
Melissa
sweetgirl_2121@yahoo.com
